Change all struct names to have the prefix "__wt_", and all corresponding typedefs to start with "WT_".

81 files changed, 1128 insertions, 1049 deletions

diff --git a/dist/log.py b/dist/log.py
index e58b2889ce5..9b992b77074 100644
--- a/dist/log.py
+++ b/dist/log.py
@@ -28,7 +28,7 @@ tfile.write('/* DO NOT EDIT: automatically built by dist/log.py. */\n')
 for t in log_data.types:
 	tfile.write('''
 static inline int
-__wt_logput_%(name)s(SESSION *session, %(param_decl)s)
+__wt_logput_%(name)s(WT_SESSION_IMPL *session, %(param_decl)s)
 {
 	return (__wt_log_put(session, &__wt_logdesc_%(name)s, %(param_list)s));
 }
diff --git a/dist/stat.py b/dist/stat.py
index 09ff6793ebe..5ee4c19f82e 100644
--- a/dist/stat.py
+++ b/dist/stat.py
@@ -45,7 +45,7 @@ def print_func(name, list):
 	f.write('\n')
 	f.write('int\n')
 	f.write('__wt_stat_alloc_' + name +
-	    '_stats(SESSION *session, WT_' +
+	    '_stats(WT_SESSION_IMPL *session, WT_' +
 	    name.upper() + '_STATS **statsp)\n')
 	f.write('{\n')
 	f.write('\tWT_' + name.upper() + '_STATS *stats;\n\n')
diff --git a/src/api/api.c b/src/api/api.c
index be93235f89f..fb903d471d7 100644
--- a/src/api/api.c
+++ b/src/api/api.c
@@ -7,7 +7,7 @@
 
 #include "wt_internal.h"
 
-static int __wt_api_arg_min(SESSION *, const char *, uint64_t, uint64_t);
+static int __wt_api_arg_min(WT_SESSION_IMPL *, const char *, uint64_t, uint64_t);
 
 /*
  * __session_close --
@@ -16,14 +16,14 @@ static int __wt_api_arg_min(SESSION *, const char *, uint64_t, uint64_t);
 static int
 __session_close(WT_SESSION *wt_session, const char *config)
 {
-	BTREE_SESSION *btree_session;
-	CONNECTION *conn;
-	SESSION *session;
+	WT_BTREE_SESSION *btree_session;
+	WT_CONNECTION_IMPL *conn;
+	WT_SESSION_IMPL *session;
 	WT_CURSOR *cursor;
 	int ret;
 
-	conn = (CONNECTION *)wt_session->connection;
-	session = (SESSION *)wt_session;
+	conn = (WT_CONNECTION_IMPL *)wt_session->connection;
+	session = (WT_SESSION_IMPL *)wt_session;
 	ret = 0;
 
 	SESSION_API_CALL(session, close, config);
@@ -55,11 +55,11 @@ static int
 __session_open_cursor(WT_SESSION *wt_session,
     const char *uri, WT_CURSOR *to_dup, const char *config, WT_CURSOR **cursorp)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 
 	WT_UNUSED(to_dup);
 
-	session = (SESSION *)wt_session;
+	session = (WT_SESSION_IMPL *)wt_session;
 	SESSION_API_CALL(session, open_cursor, config);
 
 	if (strncmp(uri, "config:", 7) == 0)
@@ -82,13 +82,13 @@ __session_open_cursor(WT_SESSION *wt_session,
 static int
 __session_create(WT_SESSION *wt_session, const char *name, const char *config)
 {
-	CONNECTION *conn;
-	SESSION *session;
+	WT_CONNECTION_IMPL *conn;
+	WT_SESSION_IMPL *session;
 	WT_CONFIG_ITEM cval;
 	const char *collapse, *key_format, *value_format;
 
-	session = (SESSION *)wt_session;
-	conn = (CONNECTION *)wt_session->connection;
+	session = (WT_SESSION_IMPL *)wt_session;
+	conn = (WT_CONNECTION_IMPL *)wt_session->connection;
 
 	SESSION_API_CALL(session, create, config);
 
@@ -139,7 +139,7 @@ __session_create(WT_SESSION *wt_session, const char *name, const char *config)
 		WT_RET(__wt_btree_create(session, name, collapse));
 	}
 
-	/* Allocate a BTREE handle, and open the underlying file. */
+	/* Allocate a WT_BTREE handle, and open the underlying file. */
 	WT_RET(__wt_btree_open(session, name, 0));
 	WT_RET(__wt_session_add_btree(session, NULL));
 
@@ -171,11 +171,11 @@ static int
 __session_drop(
     WT_SESSION *wt_session, const char *name, const char *config)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	WT_CONFIG_ITEM cval;
 	int force, ret;
 
-	session = (SESSION *)wt_session;
+	session = (WT_SESSION_IMPL *)wt_session;
 
 	SESSION_API_CALL(session, drop, config);
 	if (strncmp(name, "table:", 6) != 0) {
@@ -202,10 +202,10 @@ __session_drop(
 static int
 __session_salvage(WT_SESSION *wt_session, const char *name, const char *config)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	int ret;
 
-	session = (SESSION *)wt_session;
+	session = (WT_SESSION_IMPL *)wt_session;
 	ret = 0;
 
 	SESSION_API_CALL(session, salvage, config);
@@ -229,7 +229,7 @@ __session_salvage(WT_SESSION *wt_session, const char *name, const char *config)
 
 	WT_TRET(__wt_salvage(session, config));
 
-	/* Close the file and discard the BTREE structure. */
+	/* Close the file and discard the WT_BTREE structure. */
 	WT_TRET(__wt_btree_close(session));
 	API_END();
 
@@ -274,10 +274,10 @@ __session_truncate(WT_SESSION *wt_session,
 static int
 __session_verify(WT_SESSION *wt_session, const char *name, const char *config)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	int ret;
 
-	session = (SESSION *)wt_session;
+	session = (WT_SESSION_IMPL *)wt_session;
 	ret = 0;
 
 	SESSION_API_CALL(session, verify, config);
@@ -304,7 +304,7 @@ __session_verify(WT_SESSION *wt_session, const char *name, const char *config)
 
 	WT_TRET(__wt_verify(session, NULL, config));
 
-	/* Close the file and discard the BTREE structure. */
+	/* Close the file and discard the WT_BTREE structure. */
 	WT_TRET(__wt_btree_close(session));
 	API_END();
 
@@ -370,10 +370,10 @@ __session_checkpoint(WT_SESSION *wt_session, const char *config)
 static int
 __session_msg_printf(WT_SESSION *wt_session, const char *fmt, ...)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	va_list ap;
 
-	session = (SESSION *)wt_session;
+	session = (WT_SESSION_IMPL *)wt_session;
 
 	va_start(ap, fmt);
 	__wt_msgv(session, session->name, NULL, fmt, ap);
@@ -390,8 +390,8 @@ static int
 __conn_load_extension(WT_CONNECTION *wt_conn,
     const char *path, const char *config)
 {
-	CONNECTION *conn;
-	SESSION *session;
+	WT_CONNECTION_IMPL *conn;
+	WT_SESSION_IMPL *session;
 	const char *entry_name;
 	char namebuf[100];
 	int (*entry)(WT_CONNECTION *, const char *);
@@ -401,7 +401,7 @@ __conn_load_extension(WT_CONNECTION *wt_conn,
 
 	WT_UNUSED(path);
 
-	conn = (CONNECTION *)wt_conn;
+	conn = (WT_CONNECTION_IMPL *)wt_conn;
 	CONNECTION_API_CALL(conn, session, load_extension, config);
 
 	entry_name = "wiredtiger_extension_init";
@@ -434,13 +434,13 @@ static int
 __conn_add_cursor_type(WT_CONNECTION *wt_conn,
     const char *prefix, WT_CURSOR_TYPE *ctype, const char *config)
 {
-	CONNECTION *conn;
-	SESSION *session;
+	WT_CONNECTION_IMPL *conn;
+	WT_SESSION_IMPL *session;
 
 	WT_UNUSED(prefix);
 	WT_UNUSED(ctype);
 
-	conn = (CONNECTION *)wt_conn;
+	conn = (WT_CONNECTION_IMPL *)wt_conn;
 	CONNECTION_API_CALL(conn, session, add_cursor_type, config);
 	API_END();
 
@@ -455,13 +455,13 @@ static int
 __conn_add_collator(WT_CONNECTION *wt_conn,
     const char *name, WT_COLLATOR *collator, const char *config)
 {
-	CONNECTION *conn;
-	SESSION *session;
+	WT_CONNECTION_IMPL *conn;
+	WT_SESSION_IMPL *session;
 
 	WT_UNUSED(name);
 	WT_UNUSED(collator);
 
-	conn = (CONNECTION *)wt_conn;
+	conn = (WT_CONNECTION_IMPL *)wt_conn;
 	CONNECTION_API_CALL(conn, session, add_collator, config);
 	API_END();
 
@@ -476,13 +476,13 @@ static int
 __conn_add_compressor(WT_CONNECTION *wt_conn,
     const char *name, WT_COMPRESSOR *compressor, const char *config)
 {
-	CONNECTION *conn;
-	SESSION *session;
+	WT_CONNECTION_IMPL *conn;
+	WT_SESSION_IMPL *session;
 
 	WT_UNUSED(name);
 	WT_UNUSED(compressor);
 
-	conn = (CONNECTION *)wt_conn;
+	conn = (WT_CONNECTION_IMPL *)wt_conn;
 	CONNECTION_API_CALL(conn, session, add_collator, config);
 	API_END();
 
@@ -497,13 +497,13 @@ static int
 __conn_add_extractor(WT_CONNECTION *wt_conn,
     const char *name, WT_EXTRACTOR *extractor, const char *config)
 {
-	CONNECTION *conn;
-	SESSION *session;
+	WT_CONNECTION_IMPL *conn;
+	WT_SESSION_IMPL *session;
 
 	WT_UNUSED(name);
 	WT_UNUSED(extractor);
 
-	conn = (CONNECTION *)wt_conn;
+	conn = (WT_CONNECTION_IMPL *)wt_conn;
 	CONNECTION_API_CALL(conn, session, add_collator, config);
 	API_END();
 
@@ -513,7 +513,7 @@ __conn_add_extractor(WT_CONNECTION *wt_conn,
 static const char *
 __conn_get_home(WT_CONNECTION *wt_conn)
 {
-	return (((CONNECTION *)wt_conn)->home);
+	return (((WT_CONNECTION_IMPL *)wt_conn)->home);
 }
 
 /*
@@ -536,12 +536,12 @@ static int
 __conn_close(WT_CONNECTION *wt_conn, const char *config)
 {
 	int ret;
-	CONNECTION *conn;
-	SESSION *s, *session;
+	WT_CONNECTION_IMPL *conn;
+	WT_SESSION_IMPL *s, *session;
 	WT_SESSION *wt_session;
 
 	ret = 0;
-	conn = (CONNECTION *)wt_conn;
+	conn = (WT_CONNECTION_IMPL *)wt_conn;
 
 	CONNECTION_API_CALL(conn, session, close, config);
 
@@ -587,11 +587,11 @@ __conn_open_session(WT_CONNECTION *wt_conn,
 		__session_checkpoint,
 		__session_msg_printf,
 	};
-	CONNECTION *conn;
-	SESSION *session, *session_ret;
+	WT_CONNECTION_IMPL *conn;
+	WT_SESSION_IMPL *session, *session_ret;
 	int ret;
 
-	conn = (CONNECTION *)wt_conn;
+	conn = (WT_CONNECTION_IMPL *)wt_conn;
 	session_ret = NULL;
 	CONNECTION_API_CALL(conn, session, open_session, config);
 
@@ -615,7 +615,7 @@ __conn_open_session(WT_CONNECTION *wt_conn,
 	TAILQ_INSERT_HEAD(&conn->sessions_head, session_ret, q);
 	__wt_unlock(session, conn->mtx);
 
-	STATIC_ASSERT(offsetof(CONNECTION, iface) == 0);
+	STATIC_ASSERT(offsetof(WT_CONNECTION_IMPL, iface) == 0);
 	*wt_sessionp = &session_ret->iface;
 
 	if (0) {
@@ -661,8 +661,8 @@ wiredtiger_open(const char *home, WT_EVENT_HANDLER *event_handler,
 		{ "evict", WT_VERB_EVICT },
 		{ NULL, 0 }
 	};
-	CONNECTION *conn;
-	SESSION *session;
+	WT_CONNECTION_IMPL *conn;
+	WT_SESSION_IMPL *session;
 	WT_CONFIG subconfig;
 	WT_CONFIG_ITEM cval, skey, sval;
 	const char *__cfg[] = { __wt_confdfl_wiredtiger_open, config, NULL };
@@ -766,7 +766,7 @@ wiredtiger_open(const char *home, WT_EVENT_HANDLER *event_handler,
 	else if (ret != 0)
 		goto err;
 
-	STATIC_ASSERT(offsetof(CONNECTION, iface) == 0);
+	STATIC_ASSERT(offsetof(WT_CONNECTION_IMPL, iface) == 0);
 	*wt_connp = &conn->iface;
 
 	if (0) {
@@ -786,7 +786,7 @@ err:		if (opened)
  */
 static int
 __wt_api_arg_min(
-    SESSION *session, const char *arg_name, uint64_t v, uint64_t min)
+    WT_SESSION_IMPL *session, const char *arg_name, uint64_t v, uint64_t min)
 {
 	if (v >= min)
 		return (0);
diff --git a/src/api/config.c b/src/api/config.c
index c7a4d0f0734..2e2cd857ce2 100644
--- a/src/api/config.c
+++ b/src/api/config.c
@@ -570,7 +570,7 @@ __wt_config_getones(const char *cfg, const char *key, WT_CONFIG_ITEM *value)
  *	somewhere in the defaults.
  */
 int
-__wt_config_checklist(SESSION *session,
+__wt_config_checklist(WT_SESSION_IMPL *session,
     const char **defaults, const char *config)
 {
 	WT_CONFIG cparser;
@@ -616,7 +616,8 @@ __wt_config_checklist(SESSION *session,
  *	application-supplied config string appear somewhere in the defaults.
  */
 int
-__wt_config_check(SESSION *session, const char *defaults, const char *config)
+__wt_config_check(
+    WT_SESSION_IMPL *session, const char *defaults, const char *config)
 {
 	const char *defs[2];
 	defs[0] = defaults;
@@ -632,7 +633,7 @@ __wt_config_check(SESSION *session, const char *defaults, const char *config)
  *	buffer.
  */
 int
-__wt_config_collapse(SESSION *session,
+__wt_config_collapse(WT_SESSION_IMPL *session,
     const char **cfg, const char **config_ret)
 {
 	char *config, *end, *p;
diff --git a/src/api/cur_btree.c b/src/api/cur_btree.c
index d3c4fe1816d..8e0889b1624 100644
--- a/src/api/cur_btree.c
+++ b/src/api/cur_btree.c
@@ -15,7 +15,7 @@ static int
 __curbtree_first(WT_CURSOR *cursor)
 {
 	CURSOR_BTREE *cbt;
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	int ret;
 
 	cbt = (CURSOR_BTREE *)cursor;
@@ -34,7 +34,7 @@ static int
 __curbtree_last(WT_CURSOR *cursor)
 {
 	CURSOR_BTREE *cbt;
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 
 	cbt = (CURSOR_BTREE *)cursor;
 	CURSOR_API_CALL(cursor, session, last, cbt->btree);
@@ -51,7 +51,7 @@ static int
 __curbtree_next(WT_CURSOR *cursor)
 {
 	CURSOR_BTREE *cbt;
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	int ret;
 
 	cbt = (CURSOR_BTREE *)cursor;
@@ -70,7 +70,7 @@ static int
 __curbtree_prev(WT_CURSOR *cursor)
 {
 	CURSOR_BTREE *cbt;
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 
 	cbt = (CURSOR_BTREE *)cursor;
 	CURSOR_API_CALL(cursor, session, prev, cbt->btree);
@@ -87,7 +87,7 @@ static int
 __curbtree_search_near(WT_CURSOR *cursor, int *lastcmp)
 {
 	CURSOR_BTREE *cbt;
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	int ret;
 
 	cbt = (CURSOR_BTREE *)cursor;
@@ -106,7 +106,7 @@ static int
 __curbtree_insert(WT_CURSOR *cursor)
 {
 	CURSOR_BTREE *cbt;
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	int ret;
 
 	cbt = (CURSOR_BTREE *)cursor;
@@ -125,7 +125,7 @@ static int
 __curbtree_update(WT_CURSOR *cursor)
 {
 	CURSOR_BTREE *cbt;
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	int ret;
 
 	cbt = (CURSOR_BTREE *)cursor;
@@ -144,7 +144,7 @@ static int
 __curbtree_remove(WT_CURSOR *cursor)
 {
 	CURSOR_BTREE *cbt;
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	int ret;
 
 	cbt = (CURSOR_BTREE *)cursor;
@@ -163,7 +163,7 @@ static int
 __curbtree_close(WT_CURSOR *cursor, const char *config)
 {
 	CURSOR_BTREE *cbt;
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	int ret;
 
 	cbt = (CURSOR_BTREE *)cursor;
@@ -181,7 +181,7 @@ __curbtree_close(WT_CURSOR *cursor, const char *config)
  *	WT_SESSION->open_cursor method for the btree cursor type.
  */
 int
-__wt_curbtree_open(SESSION *session,
+__wt_curbtree_open(WT_SESSION_IMPL *session,
     const char *uri, const char *config, WT_CURSOR **cursorp)
 {
 	static WT_CURSOR iface = {
@@ -210,8 +210,8 @@ __wt_curbtree_open(SESSION *session,
 		0			/* uint32_t flags */
 	};
 	const char *tablename;
-	BTREE_SESSION *btree_session;
-	CONNECTION *conn;
+	WT_BTREE_SESSION *btree_session;
+	WT_CONNECTION_IMPL *conn;
 	CURSOR_BTREE *cbt;
 	WT_CONFIG_ITEM cval;
 	WT_CURSOR *cursor;
diff --git a/src/api/cur_bulk.c b/src/api/cur_bulk.c
index 2b3cc93519c..4f7d2b97ee2 100644
--- a/src/api/cur_bulk.c
+++ b/src/api/cur_bulk.c
@@ -14,9 +14,9 @@
 static int
 __curbulk_insert(WT_CURSOR *cursor)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	CURSOR_BULK *cbulk;
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 
 	cbulk = (CURSOR_BULK *)cursor;
 	btree = cbulk->cbt.btree;
@@ -54,9 +54,9 @@ __curbulk_insert(WT_CURSOR *cursor)
 static int
 __curbulk_close(WT_CURSOR *cursor, const char *config)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	CURSOR_BULK *cbulk;
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	int ret;
 
 	cbulk = (CURSOR_BULK *)cursor;
diff --git a/src/api/cur_config.c b/src/api/cur_config.c
index 700d06d5fe1..32ad17c0ff5 100644
--- a/src/api/cur_config.c
+++ b/src/api/cur_config.c
@@ -123,7 +123,7 @@ __curconfig_close(WT_CURSOR *cursor, const char *config)
  *	WT_SESSION->open_cursor method for config cursors.
  */
 int
-__wt_curconfig_open(SESSION *session,
+__wt_curconfig_open(WT_SESSION_IMPL *session,
     const char *uri, const char *config, WT_CURSOR **cursorp)
 {
 	static WT_CURSOR iface = {
diff --git a/src/api/cur_dump.c b/src/api/cur_dump.c
index 64f316f5052..0ed421eaa59 100644
--- a/src/api/cur_dump.c
+++ b/src/api/cur_dump.c
@@ -13,7 +13,7 @@
  *	convert it to a dumpable string.
  */
 static int
-__convert_to_dump(SESSION *session, WT_BUF *buf)
+__convert_to_dump(WT_SESSION_IMPL *session, WT_BUF *buf)
 {
 	WT_UNUSED(session);
 	WT_UNUSED(buf);
@@ -27,7 +27,7 @@ __convert_to_dump(SESSION *session, WT_BUF *buf)
  *	convert it to a raw value.
  */
 static int
-__convert_from_dump(SESSION *session, WT_BUF *buf)
+__convert_from_dump(WT_SESSION_IMPL *session, WT_BUF *buf)
 {
 	WT_UNUSED(session);
 	WT_UNUSED(buf);
@@ -42,7 +42,7 @@ __convert_from_dump(SESSION *session, WT_BUF *buf)
 static int
 __curdump_get_key(WT_CURSOR *cursor, ...)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	WT_ITEM *key;
 	va_list ap;
 
@@ -73,7 +73,7 @@ __curdump_get_key(WT_CURSOR *cursor, ...)
 static int
 __curdump_get_value(WT_CURSOR *cursor, ...)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	WT_ITEM *value;
 	va_list ap;
 
@@ -103,7 +103,7 @@ __curdump_get_value(WT_CURSOR *cursor, ...)
 static void
 __curdump_set_key(WT_CURSOR *cursor, ...)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	va_list ap;
 	int ret;
 
@@ -130,7 +130,7 @@ __curdump_set_key(WT_CURSOR *cursor, ...)
 static void
 __curdump_set_value(WT_CURSOR *cursor, ...)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	va_list ap;
 	int ret;
 
diff --git a/src/api/cur_stat.c b/src/api/cur_stat.c
index c11711227d3..4a7cfe358e9 100644
--- a/src/api/cur_stat.c
+++ b/src/api/cur_stat.c
@@ -14,7 +14,7 @@
 static int
 __curstat_first(WT_CURSOR *cursor)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	int ret;
 
 	CURSOR_API_CALL(cursor, session, first, NULL);
@@ -31,7 +31,7 @@ __curstat_first(WT_CURSOR *cursor)
 static int
 __curstat_last(WT_CURSOR *cursor)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	int ret;
 
 	CURSOR_API_CALL(cursor, session, last, NULL);
@@ -48,7 +48,7 @@ __curstat_last(WT_CURSOR *cursor)
 static int
 __curstat_next(WT_CURSOR *cursor)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	int ret;
 
 	CURSOR_API_CALL(cursor, session, next, NULL);
@@ -65,7 +65,7 @@ __curstat_next(WT_CURSOR *cursor)
 static int
 __curstat_prev(WT_CURSOR *cursor)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	int ret;
 
 	CURSOR_API_CALL(cursor, session, prev, NULL);
@@ -82,7 +82,7 @@ __curstat_prev(WT_CURSOR *cursor)
 static int
 __curstat_search_near(WT_CURSOR *cursor, int *lastcmp)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	int ret;
 
 	WT_UNUSED(lastcmp);
@@ -101,7 +101,7 @@ __curstat_search_near(WT_CURSOR *cursor, int *lastcmp)
 static int
 __curstat_insert(WT_CURSOR *cursor)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	int ret;
 
 	CURSOR_API_CALL(cursor, session, insert, NULL);
@@ -118,7 +118,7 @@ __curstat_insert(WT_CURSOR *cursor)
 static int
 __curstat_update(WT_CURSOR *cursor)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	int ret;
 
 	CURSOR_API_CALL(cursor, session, update, NULL);
@@ -135,7 +135,7 @@ __curstat_update(WT_CURSOR *cursor)
 static int
 __curstat_remove(WT_CURSOR *cursor)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	int ret;
 
 	CURSOR_API_CALL(cursor, session, insert, NULL);
@@ -152,7 +152,7 @@ __curstat_remove(WT_CURSOR *cursor)
 static int
 __curstat_close(WT_CURSOR *cursor, const char *config)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	int ret;
 
 	CURSOR_API_CALL_CONF(cursor, session, close, NULL, config);
@@ -168,7 +168,7 @@ __curstat_close(WT_CURSOR *cursor, const char *config)
  *	WT_SESSION->open_cursor method for the btree cursor type.
  */
 int
-__wt_curstat_open(SESSION *session,
+__wt_curstat_open(WT_SESSION_IMPL *session,
     const char *uri, const char *config, WT_CURSOR **cursorp)
 {
 	static WT_CURSOR iface = {
diff --git a/src/api/cur_std.c b/src/api/cur_std.c
index 03424d23953..59eda5e97fa 100644
--- a/src/api/cur_std.c
+++ b/src/api/cur_std.c
@@ -14,7 +14,7 @@
 static int
 __cursor_get_key(WT_CURSOR *cursor, ...)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	const char *fmt;
 	va_list ap;
 	int ret;
@@ -38,7 +38,7 @@ __cursor_get_key(WT_CURSOR *cursor, ...)
 static int
 __cursor_get_value(WT_CURSOR *cursor, ...)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	const char *fmt;
 	va_list ap;
 	int ret;
@@ -62,7 +62,7 @@ __cursor_get_value(WT_CURSOR *cursor, ...)
 static void
 __cursor_set_key(WT_CURSOR *cursor, ...)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	WT_BUF *buf;
 	WT_ITEM *item;
 	const char *fmt, *str;
@@ -116,7 +116,7 @@ __cursor_set_key(WT_CURSOR *cursor, ...)
 static void
 __cursor_set_value(WT_CURSOR *cursor, ...)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	WT_BUF *buf;
 	WT_ITEM *item;
 	const char *fmt, *str;
@@ -180,7 +180,7 @@ __cursor_search(WT_CURSOR *cursor)
 int
 __wt_cursor_close(WT_CURSOR *cursor, const char *config)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	int ret;
 
 	CURSOR_API_CALL_CONF(cursor, session, close, NULL, config);
diff --git a/src/api/session_btree.c b/src/api/session_btree.c
index b3743ea4e9d..eac01dad5ec 100644
--- a/src/api/session_btree.c
+++ b/src/api/session_btree.c
@@ -12,12 +12,13 @@
  *	Add a btree handle to the session's cache.
  */
 int
-__wt_session_add_btree(SESSION *session, BTREE_SESSION **btree_sessionp)
+__wt_session_add_btree(
+    WT_SESSION_IMPL *session, WT_BTREE_SESSION **btree_sessionp)
 {
 	const char *config;
 	char *format;
-	BTREE_SESSION *btree_session;
-	CONNECTION *conn;
+	WT_BTREE_SESSION *btree_session;
+	WT_CONNECTION_IMPL *conn;
 	WT_CONFIG_ITEM cval;
 
 	WT_RET(__wt_calloc_def(session, 1, &btree_session));
@@ -26,8 +27,8 @@ __wt_session_add_btree(SESSION *session, BTREE_SESSION **btree_sessionp)
 
 	/*
 	 * Make a copy of the key and value format, it's easier for everyone
-	 * if they are NUL-terminated.  They live in the BTREE_SESSION to save
-	 * allocating memory on every cursor open.
+         * if they are NUL-terminated.  They live in the WT_BTREE_SESSION to
+         * save allocating memory on every cursor open.
 	 */
 	config = session->btree->config;
 
@@ -58,11 +59,11 @@ __wt_session_add_btree(SESSION *session, BTREE_SESSION **btree_sessionp)
  *	Get the btree handle for the named table.
  */
 int
-__wt_session_get_btree(SESSION *session,
-    const char *name, size_t namelen, BTREE_SESSION **btree_sessionp)
+__wt_session_get_btree(WT_SESSION_IMPL *session,
+    const char *name, size_t namelen, WT_BTREE_SESSION **btree_sessionp)
 {
-	BTREE *btree;
-	BTREE_SESSION *btree_session;
+	WT_BTREE *btree;
+	WT_BTREE_SESSION *btree_session;
 
 	TAILQ_FOREACH(btree_session, &session->btrees, q) {
 		btree = btree_session->btree;
@@ -81,9 +82,10 @@ __wt_session_get_btree(SESSION *session,
  *	Remove the btree handle from the session, closing if necessary.
  */
 int
-__wt_session_remove_btree(SESSION *session, BTREE_SESSION *btree_session)
+__wt_session_remove_btree(
+    WT_SESSION_IMPL *session, WT_BTREE_SESSION *btree_session)
 {
-	CONNECTION *conn;
+	WT_CONNECTION_IMPL *conn;
 	int need_close;
 
 	conn = S2C(session);
diff --git a/src/btree/bt_alloc.c b/src/btree/bt_alloc.c
index e244cf8ee4a..50b8605b7e2 100644
--- a/src/btree/bt_alloc.c
+++ b/src/btree/bt_alloc.c
@@ -7,17 +7,17 @@
 
 #include "wt_internal.h"
 
-static void __wt_block_extend(SESSION *, uint32_t *, uint32_t);
-static int __wt_block_truncate(SESSION *);
+static void __wt_block_extend(WT_SESSION_IMPL *, uint32_t *, uint32_t);
+static int __wt_block_truncate(WT_SESSION_IMPL *);
 
 /*
  * __wt_block_alloc --
  *	Alloc a chunk of space from the underlying file.
  */
 int
-__wt_block_alloc(SESSION *session, uint32_t *addrp, uint32_t size)
+__wt_block_alloc(WT_SESSION_IMPL *session, uint32_t *addrp, uint32_t size)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_FREE_ENTRY *fe, *new;
 
 	btree = session->btree;
@@ -79,9 +79,9 @@ __wt_block_alloc(SESSION *session, uint32_t *addrp, uint32_t size)
  *	Extend the file to allocate space.
  */
 static void
-__wt_block_extend(SESSION *session, uint32_t *addrp, uint32_t size)
+__wt_block_extend(WT_SESSION_IMPL *session, uint32_t *addrp, uint32_t size)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_FH *fh;
 
 	btree = session->btree;
@@ -101,9 +101,9 @@ __wt_block_extend(SESSION *session, uint32_t *addrp, uint32_t size)
  *	Free a chunk of space to the underlying file.
  */
 int
-__wt_block_free(SESSION *session, uint32_t addr, uint32_t size)
+__wt_block_free(WT_SESSION_IMPL *session, uint32_t addr, uint32_t size)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_FREE_ENTRY *fe, *new;
 
 	btree = session->btree;
@@ -231,10 +231,10 @@ combine:/*
  *	Read the free-list at the tail of the file.
  */
 int
-__wt_block_read(SESSION *session)
+__wt_block_read(WT_SESSION_IMPL *session)
 {
 	WT_BUF *tmp;
-	BTREE *btree;
+	WT_BTREE *btree;
 	uint32_t *p;
 	int ret;
 
@@ -268,9 +268,9 @@ err:	if (tmp != NULL)
  *	Write the free-list at the tail of the file.
  */
 int
-__wt_block_write(SESSION *session)
+__wt_block_write(WT_SESSION_IMPL *session)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_BUF *tmp;
 	WT_FREE_ENTRY *fe;
 	WT_PAGE_DISK *dsk;
@@ -351,9 +351,9 @@ err:	if (tmp != NULL)
  *	Truncate the file if the last part of the file isn't in use.
  */
 static int
-__wt_block_truncate(SESSION *session)
+__wt_block_truncate(WT_SESSION_IMPL *session)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_FH *fh;
 	WT_FREE_ENTRY *fe;
 	int need_trunc;
@@ -391,9 +391,9 @@ __wt_block_truncate(SESSION *session)
  *	Discard any free-list entries.
  */
 void
-__wt_block_discard(SESSION *session)
+__wt_block_discard(WT_SESSION_IMPL *session)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_FREE_ENTRY *fe;
 
 	btree = session->btree;
@@ -409,9 +409,9 @@ __wt_block_discard(SESSION *session)
 
 #ifdef HAVE_DIAGNOSTIC
 void
-__wt_block_dump(SESSION *session)
+__wt_block_dump(WT_SESSION_IMPL *session)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_FREE_ENTRY *fe;
 
 	btree = session->btree;
diff --git a/src/btree/bt_bulk.c b/src/btree/bt_bulk.c
index a1f70b053a2..7169e61ec6b 100644
--- a/src/btree/bt_bulk.c
+++ b/src/btree/bt_bulk.c
@@ -20,10 +20,10 @@ static int __wt_bulk_row_page(CURSOR_BULK *);
 int
 __wt_bulk_init(CURSOR_BULK *cbulk)
 {
-	BTREE *btree;
-	SESSION *session;
+	WT_BTREE *btree;
+	WT_SESSION_IMPL *session;
 
-	session = (SESSION *)cbulk->cbt.iface.session;
+	session = (WT_SESSION_IMPL *)cbulk->cbt.iface.session;
 	btree = session->btree;
 
 	/*
@@ -75,10 +75,10 @@ __wt_bulk_init(CURSOR_BULK *cbulk)
 int
 __wt_bulk_insert(CURSOR_BULK *cbulk)
 {
-	BTREE *btree;
-	SESSION *session;
+	WT_BTREE *btree;
+	WT_SESSION_IMPL *session;
 
-	session = (SESSION *)cbulk->cbt.iface.session;
+	session = (WT_SESSION_IMPL *)cbulk->cbt.iface.session;
 	btree = session->btree;
 
 	/*
@@ -118,12 +118,12 @@ __wt_bulk_insert(CURSOR_BULK *cbulk)
 static int
 __wt_bulk_col(CURSOR_BULK *cbulk)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	WT_CURSOR *cursor;
 	WT_UPDATE *upd;
 	int ret;
 
-	session = (SESSION *)cbulk->cbt.iface.session;
+	session = (WT_SESSION_IMPL *)cbulk->cbt.iface.session;
 	cursor = &cbulk->cbt.iface;
 	upd = NULL;
 
@@ -153,13 +153,13 @@ err:	if (upd != NULL)
 static int
 __wt_bulk_row(CURSOR_BULK *cbulk)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	WT_CURSOR *cursor;
 	WT_INSERT *ins;
 	WT_UPDATE *upd;
 	int ret;
 
-	session = (SESSION *)cbulk->cbt.iface.session;
+	session = (WT_SESSION_IMPL *)cbulk->cbt.iface.session;
 	cursor = &cbulk->cbt.iface;
 	ins = NULL;
 	upd = NULL;
@@ -194,11 +194,11 @@ err:	if (ins != NULL)
 int
 __wt_bulk_end(CURSOR_BULK *cbulk)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	WT_PAGE *page;
 	WT_REF *root_page;
 
-	session = (SESSION *)cbulk->cbt.iface.session;
+	session = (WT_SESSION_IMPL *)cbulk->cbt.iface.session;
 
 	/* If the page has entries, reconcile and discard it. */
 	if (cbulk->ins_cnt != 0)
@@ -256,11 +256,11 @@ __wt_bulk_end(CURSOR_BULK *cbulk)
 static int
 __wt_bulk_row_page(CURSOR_BULK *cbulk)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	WT_PAGE *page;
 	WT_ROW_REF *rref;
 
-	session = (SESSION *)cbulk->cbt.iface.session;
+	session = (WT_SESSION_IMPL *)cbulk->cbt.iface.session;
 
 	/*
 	 * Take a copy of the first key for the parent; re-allocate the parent
@@ -310,10 +310,10 @@ __wt_bulk_row_page(CURSOR_BULK *cbulk)
 static int
 __wt_bulk_col_page(CURSOR_BULK *cbulk)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	WT_PAGE *page;
 
-	session = (SESSION *)cbulk->cbt.iface.session;
+	session = (WT_SESSION_IMPL *)cbulk->cbt.iface.session;
 
 	/*
 	 * Take a copy of the first key for the parent; re-allocate the parent
diff --git a/src/btree/bt_cache.c b/src/btree/bt_cache.c
index 779603aa56c..738a8bd5d2f 100644
--- a/src/btree/bt_cache.c
+++ b/src/btree/bt_cache.c
@@ -13,10 +13,10 @@
  *	Create the underlying cache.
  */
 int
-__wt_cache_create(CONNECTION *conn)
+__wt_cache_create(WT_CONNECTION_IMPL *conn)
 {
 	WT_CACHE *cache;
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	int ret;
 
 	session = &conn->default_session;
@@ -47,7 +47,7 @@ err:	__wt_cache_destroy(conn);
  *	Update the cache statistics for return to the application.
  */
 void
-__wt_cache_stats_update(CONNECTION *conn)
+__wt_cache_stats_update(WT_CONNECTION_IMPL *conn)
 {
 	WT_CACHE *cache;
 
@@ -64,9 +64,9 @@ __wt_cache_stats_update(CONNECTION *conn)
  *	Discard the underlying cache.
  */
 void
-__wt_cache_destroy(CONNECTION *conn)
+__wt_cache_destroy(WT_CONNECTION_IMPL *conn)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	WT_CACHE *cache;
 
 	session = &conn->default_session;
diff --git a/src/btree/bt_cell.c b/src/btree/bt_cell.c
index d1c8bca3965..a1dbca812aa 100644
--- a/src/btree/bt_cell.c
+++ b/src/btree/bt_cell.c
@@ -258,9 +258,9 @@ __wt_cell_len(WT_CELL *cell)
  *	Copy an on-page cell into a return buffer, processing as needed.
  */
 int
-__wt_cell_copy(SESSION *session, WT_CELL *cell, WT_BUF *retb)
+__wt_cell_copy(WT_SESSION_IMPL *session, WT_CELL *cell, WT_BUF *retb)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_OFF ovfl;
 	uint32_t size;
 	const void *p;
diff --git a/src/btree/bt_cmp.c b/src/btree/bt_cmp.c
index 1137b4afbf6..e6ebe4cd7f6 100644
--- a/src/btree/bt_cmp.c
+++ b/src/btree/bt_cmp.c
@@ -13,13 +13,13 @@
  */
 int
 __wt_bt_lex_compare(
-    BTREE *btree, const WT_ITEM *user_item, const WT_ITEM *tree_item)
+    WT_BTREE *btree, const WT_ITEM *user_item, const WT_ITEM *tree_item)
 {
 	uint32_t len;
 	const uint8_t *userp, *treep;
 
 	/*
-	 * The BTREE * argument isn't used by the default routine, but is
+	 * The WT_BTREE * argument isn't used by the default routine, but is
 	 * a standard argument for user-specified comparison functions.
 	 */
 	WT_UNUSED(btree);
@@ -51,7 +51,7 @@ __wt_bt_lex_compare(
  */
 int
 __wt_bt_int_compare(
-    BTREE *btree, const WT_ITEM *user_item, const WT_ITEM *tree_item)
+    WT_BTREE *btree, const WT_ITEM *user_item, const WT_ITEM *tree_item)
 {
 	uint64_t user_int, tree_int;
 
diff --git a/src/btree/bt_cursor.c b/src/btree/bt_cursor.c
index 1ec0b5e095e..c63dbeab3cc 100644
--- a/src/btree/bt_cursor.c
+++ b/src/btree/bt_cursor.c
@@ -16,9 +16,9 @@
 int
 __wt_btcur_first(CURSOR_BTREE *cbt)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 
-	session = (SESSION *)cbt->iface.session;
+	session = (WT_SESSION_IMPL *)cbt->iface.session;
 
 	WT_RET(__wt_walk_begin(session, NULL, &cbt->walk, 0));
 	F_SET(&cbt->iface, WT_CURSTD_POSITIONED);
@@ -123,12 +123,12 @@ __btcur_next_rle(CURSOR_BTREE *cbt, wiredtiger_recno_t *recnop, WT_BUF *value)
 static inline int
 __btcur_next_var(CURSOR_BTREE *cbt, wiredtiger_recno_t *recnop, WT_BUF *value)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	WT_CELL *cell;
 	WT_UPDATE *upd;
 	int found;
 
-	session = (SESSION *)cbt->iface.session;
+	session = (WT_SESSION_IMPL *)cbt->iface.session;
 
 	/* New page? */
 	if (cbt->nitems == 0) {
@@ -183,12 +183,12 @@ __btcur_next_var(CURSOR_BTREE *cbt, wiredtiger_recno_t *recnop, WT_BUF *value)
 static inline int
 __btcur_next_row(CURSOR_BTREE *cbt, WT_BUF *key, WT_BUF *value)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	WT_CELL *cell;
 	WT_UPDATE *upd;
 	int found;
 
-	session = (SESSION *)cbt->iface.session;
+	session = (WT_SESSION_IMPL *)cbt->iface.session;
 
 	/* New page? */
 	if (cbt->nitems == 0) {
@@ -254,12 +254,12 @@ __btcur_next_row(CURSOR_BTREE *cbt, WT_BUF *key, WT_BUF *value)
 int
 __wt_btcur_next(CURSOR_BTREE *cbt)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	WT_CURSOR *cursor;
 	int ret;
 
 	cursor = &cbt->iface;
-	session = (SESSION *)cbt->iface.session;
+	session = (WT_SESSION_IMPL *)cbt->iface.session;
 
 	if (cbt->walk.tree == NULL)
 		return (__wt_btcur_first(cbt));
@@ -322,14 +322,14 @@ __wt_btcur_prev(CURSOR_BTREE *cbt)
 int
 __wt_btcur_search_near(CURSOR_BTREE *cbt, int *exact)
 {
-	BTREE *btree;
-	SESSION *session;
+	WT_BTREE *btree;
+	WT_SESSION_IMPL *session;
 	WT_CURSOR *cursor;
 	int ret;
 
 	btree = cbt->btree;
 	cursor = &cbt->iface;
-	session = (SESSION *)cursor->session;
+	session = (WT_SESSION_IMPL *)cursor->session;
 
 	*exact = 0;
 	switch (btree->type) {
@@ -359,13 +359,13 @@ __wt_btcur_search_near(CURSOR_BTREE *cbt, int *exact)
 int
 __wt_btcur_insert(CURSOR_BTREE *cbt)
 {
-	BTREE *btree;
-	SESSION *session;
+	WT_BTREE *btree;
+	WT_SESSION_IMPL *session;
 	WT_CURSOR *cursor;
 
 	btree = cbt->btree;
 	cursor = &cbt->iface;
-	session = (SESSION *)cursor->session;
+	session = (WT_SESSION_IMPL *)cursor->session;
 
 	switch (btree->type) {
 	case BTREE_COL_FIX:
@@ -387,13 +387,13 @@ __wt_btcur_insert(CURSOR_BTREE *cbt)
 int
 __wt_btcur_update(CURSOR_BTREE *cbt)
 {
-	BTREE *btree;
-	SESSION *session;
+	WT_BTREE *btree;
+	WT_SESSION_IMPL *session;
 	WT_CURSOR *cursor;
 
 	btree = cbt->btree;
 	cursor = &cbt->iface;
-	session = (SESSION *)cursor->session;
+	session = (WT_SESSION_IMPL *)cursor->session;
 
 	switch (btree->type) {
 	case BTREE_COL_FIX:
@@ -415,13 +415,13 @@ __wt_btcur_update(CURSOR_BTREE *cbt)
 int
 __wt_btcur_remove(CURSOR_BTREE *cbt)
 {
-	BTREE *btree;
-	SESSION *session;
+	WT_BTREE *btree;
+	WT_SESSION_IMPL *session;
 	WT_CURSOR *cursor;
 
 	btree = cbt->btree;
 	cursor = &cbt->iface;
-	session = (SESSION *)cursor->session;
+	session = (WT_SESSION_IMPL *)cursor->session;
 
 	switch (btree->type) {
 	case BTREE_COL_FIX:
@@ -441,11 +441,11 @@ __wt_btcur_remove(CURSOR_BTREE *cbt)
 int
 __wt_btcur_close(CURSOR_BTREE *cbt, const char *config)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 
 	WT_UNUSED(config);
 
-	session = (SESSION *)cbt->iface.session;
+	session = (WT_SESSION_IMPL *)cbt->iface.session;
 	__wt_walk_end(session, &cbt->walk);
 	return (0);
 }
diff --git a/src/btree/bt_debug.c b/src/btree/bt_debug.c
index 0f3dfbdb9d8..a78be45fee2 100644
--- a/src/btree/bt_debug.c
+++ b/src/btree/bt_debug.c
@@ -10,21 +10,24 @@
 #include "cell.i"
 
 #ifdef HAVE_DIAGNOSTIC
-static int  __wt_debug_cell(SESSION *, WT_CELL *, FILE *fp);
-static int  __wt_debug_cell_data(SESSION *, WT_CELL *, FILE *);
+static int  __wt_debug_cell(WT_SESSION_IMPL *, WT_CELL *, FILE *fp);
+static int  __wt_debug_cell_data(WT_SESSION_IMPL *, WT_CELL *, FILE *);
 static void __wt_debug_col_insert(WT_INSERT *, FILE *);
-static int  __wt_debug_dsk_cell(SESSION *, WT_PAGE_DISK *, FILE *);
-static void __wt_debug_dsk_col_fix(BTREE *, WT_PAGE_DISK *, FILE *);
+static int  __wt_debug_dsk_cell(WT_SESSION_IMPL *, WT_PAGE_DISK *, FILE *);
+static void __wt_debug_dsk_col_fix(WT_BTREE *, WT_PAGE_DISK *, FILE *);
 static void __wt_debug_dsk_col_int(WT_PAGE_DISK *, FILE *);
-static void __wt_debug_dsk_col_rle(BTREE *, WT_PAGE_DISK *, FILE *);
-static void __wt_debug_page_col_fix(SESSION *, WT_PAGE *, FILE *);
-static int  __wt_debug_page_col_int(SESSION *, WT_PAGE *, FILE *, uint32_t);
-static void __wt_debug_page_col_rle(SESSION *, WT_PAGE *, FILE *);
-static int  __wt_debug_page_col_var(SESSION *, WT_PAGE *, FILE *);
+static void __wt_debug_dsk_col_rle(WT_BTREE *, WT_PAGE_DISK *, FILE *);
+static void __wt_debug_page_col_fix(WT_SESSION_IMPL *, WT_PAGE *, FILE *);
+static int  __wt_debug_page_col_int(
+        WT_SESSION_IMPL *, WT_PAGE *, FILE *, uint32_t);
+static void __wt_debug_page_col_rle(WT_SESSION_IMPL *, WT_PAGE *, FILE *);
+static int  __wt_debug_page_col_var(WT_SESSION_IMPL *, WT_PAGE *, FILE *);
 static void __wt_debug_page_flags(WT_PAGE *, FILE *);
-static int  __wt_debug_page_row_int(SESSION *, WT_PAGE *, FILE *, uint32_t);
-static int  __wt_debug_page_row_leaf(SESSION *, WT_PAGE *, FILE *);
-static int  __wt_debug_page_work(SESSION *, WT_PAGE *, FILE *, uint32_t);
+static int  __wt_debug_page_row_int(
+        WT_SESSION_IMPL *, WT_PAGE *, FILE *, uint32_t);
+static int  __wt_debug_page_row_leaf(WT_SESSION_IMPL *, WT_PAGE *, FILE *);
+static int  __wt_debug_page_work(
+        WT_SESSION_IMPL *, WT_PAGE *, FILE *, uint32_t);
 static void __wt_debug_pair(const char *, const void *, uint32_t, FILE *);
 static void __wt_debug_ref(WT_REF *, FILE *);
 static void __wt_debug_row_insert(WT_INSERT *, FILE *);
@@ -66,7 +69,7 @@ __wt_debug_set_fp(const char *ofile, FILE **fpp, int *close_varp)
  *	open.
  */
 int
-__wt_debug_dump(SESSION *session, const char *ofile, FILE *fp)
+__wt_debug_dump(WT_SESSION_IMPL *session, const char *ofile, FILE *fp)
 {
 	int do_close, ret;
 
@@ -90,8 +93,8 @@ __wt_debug_dump(SESSION *session, const char *ofile, FILE *fp)
  *	Read and dump a disk page in debugging mode.
  */
 int
-__wt_debug_addr(
-    SESSION *session, uint32_t addr, uint32_t size, const char *ofile, FILE *fp)
+__wt_debug_addr(WT_SESSION_IMPL *session,
+    uint32_t addr, uint32_t size, const char *ofile, FILE *fp)
 {
 	int do_close, ret;
 	char *bp;
@@ -119,9 +122,9 @@ err:	__wt_free(session, bp);
  */
 int
 __wt_debug_disk(
-    SESSION *session, WT_PAGE_DISK *dsk, const char *ofile, FILE *fp)
+    WT_SESSION_IMPL *session, WT_PAGE_DISK *dsk, const char *ofile, FILE *fp)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	int do_close, ret;
 
 	btree = session->btree;
@@ -192,7 +195,7 @@ __wt_debug_disk(
  */
 int
 __wt_debug_tree_all(
-    SESSION *session, WT_PAGE *page, const char *ofile, FILE *fp)
+    WT_SESSION_IMPL *session, WT_PAGE *page, const char *ofile, FILE *fp)
 {
 	int do_close, ret;
 
@@ -216,7 +219,8 @@ __wt_debug_tree_all(
  *	Dump the in-memory information for a tree, not including leaf pages.
  */
 int
-__wt_debug_tree(SESSION *session, WT_PAGE *page, const char *ofile, FILE *fp)
+__wt_debug_tree(
+    WT_SESSION_IMPL *session, WT_PAGE *page, const char *ofile, FILE *fp)
 {
 	int do_close, ret;
 
@@ -239,7 +243,8 @@ __wt_debug_tree(SESSION *session, WT_PAGE *page, const char *ofile, FILE *fp)
  *	Dump the in-memory information for a page.
  */
 int
-__wt_debug_page(SESSION *session, WT_PAGE *page, const char *ofile, FILE *fp)
+__wt_debug_page(
+    WT_SESSION_IMPL *session, WT_PAGE *page, const char *ofile, FILE *fp)
 {
 	int do_close, ret;
 
@@ -258,9 +263,10 @@ __wt_debug_page(SESSION *session, WT_PAGE *page, const char *ofile, FILE *fp)
  *	Dump the in-memory information for an in-memory page.
  */
 static int
-__wt_debug_page_work(SESSION *session, WT_PAGE *page, FILE *fp, uint32_t flags)
+__wt_debug_page_work(
+    WT_SESSION_IMPL *session, WT_PAGE *page, FILE *fp, uint32_t flags)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 
 	btree = session->btree;
 
@@ -357,7 +363,7 @@ __wt_debug_page_flags(WT_PAGE *page, FILE *fp)
  *	Dump an in-memory WT_PAGE_COL_FIX page.
  */
 static void
-__wt_debug_page_col_fix(SESSION *session, WT_PAGE *page, FILE *fp)
+__wt_debug_page_col_fix(WT_SESSION_IMPL *session, WT_PAGE *page, FILE *fp)
 {
 	WT_COL *cip;
 	WT_UPDATE *upd;
@@ -389,7 +395,7 @@ __wt_debug_page_col_fix(SESSION *session, WT_PAGE *page, FILE *fp)
  */
 static int
 __wt_debug_page_col_int(
-    SESSION *session, WT_PAGE *page, FILE *fp, uint32_t flags)
+    WT_SESSION_IMPL *session, WT_PAGE *page, FILE *fp, uint32_t flags)
 {
 	WT_COL_REF *cref;
 	uint32_t i;
@@ -418,7 +424,7 @@ __wt_debug_page_col_int(
  *	Dump an in-memory WT_PAGE_COL_RLE page.
  */
 static void
-__wt_debug_page_col_rle(SESSION *session, WT_PAGE *page, FILE *fp)
+__wt_debug_page_col_rle(WT_SESSION_IMPL *session, WT_PAGE *page, FILE *fp)
 {
 	WT_COL *cip;
 	WT_INSERT *ins;
@@ -451,7 +457,7 @@ __wt_debug_page_col_rle(SESSION *session, WT_PAGE *page, FILE *fp)
  *	Dump an in-memory WT_PAGE_COL_VAR page.
  */
 static int
-__wt_debug_page_col_var(SESSION *session, WT_PAGE *page, FILE *fp)
+__wt_debug_page_col_var(WT_SESSION_IMPL *session, WT_PAGE *page, FILE *fp)
 {
 	WT_COL *cip;
 	WT_UPDATE *upd;
@@ -478,7 +484,7 @@ __wt_debug_page_col_var(SESSION *session, WT_PAGE *page, FILE *fp)
  */
 static int
 __wt_debug_page_row_int(
-    SESSION *session, WT_PAGE *page, FILE *fp, uint32_t flags)
+    WT_SESSION_IMPL *session, WT_PAGE *page, FILE *fp, uint32_t flags)
 {
 	WT_ROW_REF *rref;
 	uint32_t i;
@@ -512,7 +518,7 @@ __wt_debug_page_row_int(
  *	Dump an in-memory WT_PAGE_ROW_LEAF page.
  */
 static int
-__wt_debug_page_row_leaf(SESSION *session, WT_PAGE *page, FILE *fp)
+__wt_debug_page_row_leaf(WT_SESSION_IMPL *session, WT_PAGE *page, FILE *fp)
 {
 	WT_INSERT *ins;
 	WT_ROW *rip;
@@ -611,7 +617,7 @@ __wt_debug_update(WT_UPDATE *upd, FILE *fp)
  *	Dump a page of WT_CELL's.
  */
 static int
-__wt_debug_dsk_cell(SESSION *session, WT_PAGE_DISK *dsk, FILE *fp)
+__wt_debug_dsk_cell(WT_SESSION_IMPL *session, WT_PAGE_DISK *dsk, FILE *fp)
 {
 	WT_CELL *cell;
 	uint32_t i;
@@ -629,7 +635,7 @@ __wt_debug_dsk_cell(SESSION *session, WT_PAGE_DISK *dsk, FILE *fp)
  *	Dump a single WT_CELL.
  */
 static int
-__wt_debug_cell(SESSION *session, WT_CELL *cell, FILE *fp)
+__wt_debug_cell(WT_SESSION_IMPL *session, WT_CELL *cell, FILE *fp)
 {
 	WT_OFF off;
 
@@ -687,7 +693,7 @@ __wt_debug_dsk_col_int(WT_PAGE_DISK *dsk, FILE *fp)
  *	Dump a WT_PAGE_COL_FIX page.
  */
 static void
-__wt_debug_dsk_col_fix(BTREE *btree, WT_PAGE_DISK *dsk, FILE *fp)
+__wt_debug_dsk_col_fix(WT_BTREE *btree, WT_PAGE_DISK *dsk, FILE *fp)
 {
 	uint32_t i;
 	uint8_t *p;
@@ -710,7 +716,7 @@ __wt_debug_dsk_col_fix(BTREE *btree, WT_PAGE_DISK *dsk, FILE *fp)
  *	Dump a WT_PAGE_COL_RLE page.
  */
 static void
-__wt_debug_dsk_col_rle(BTREE *btree, WT_PAGE_DISK *dsk, FILE *fp)
+__wt_debug_dsk_col_rle(WT_BTREE *btree, WT_PAGE_DISK *dsk, FILE *fp)
 {
 	uint32_t i;
 	uint8_t *p;
@@ -735,7 +741,7 @@ __wt_debug_dsk_col_rle(BTREE *btree, WT_PAGE_DISK *dsk, FILE *fp)
  *	Dump a single cell's data in debugging mode.
  */
 static int
-__wt_debug_cell_data(SESSION *session, WT_CELL *cell, FILE *fp)
+__wt_debug_cell_data(WT_SESSION_IMPL *session, WT_CELL *cell, FILE *fp)
 {
 	WT_BUF *tmp;
 	uint32_t size;
diff --git a/src/btree/bt_desc.c b/src/btree/bt_desc.c
index c11986f8731..087cb56c5ab 100644
--- a/src/btree/bt_desc.c
+++ b/src/btree/bt_desc.c
@@ -12,9 +12,9 @@
  *	Read and verify the file's metadata.
  */
 int
-__wt_desc_read(SESSION *session)
+__wt_desc_read(WT_SESSION_IMPL *session)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_BTREE_DESC *desc;
 	WT_CONFIG_ITEM cval;
 	uint8_t *p, *ep, buf[512];
@@ -93,7 +93,7 @@ eof:		__wt_errx(session,
  *	Write the file's descriptor structure.
  */
 int
-__wt_desc_write(SESSION *session, const char *config, WT_FH *fh)
+__wt_desc_write(WT_SESSION_IMPL *session, const char *config, WT_FH *fh)
 {
 	WT_BTREE_DESC *desc;
 	uint8_t buf[512];
@@ -119,9 +119,9 @@ __wt_desc_write(SESSION *session, const char *config, WT_FH *fh)
  *	Update the file's descriptor structure.
  */
 int
-__wt_desc_update(SESSION *session)
+__wt_desc_update(WT_SESSION_IMPL *session)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_BTREE_DESC *desc;
 	uint8_t buf[512];
 
diff --git a/src/btree/bt_discard.c b/src/btree/bt_discard.c
index 0494818eccd..b0c0a345dfb 100644
--- a/src/btree/bt_discard.c
+++ b/src/btree/bt_discard.c
@@ -8,16 +8,16 @@
 #include "wt_internal.h"
 #include "btree.i"
 
-static void __wt_free_insert(SESSION *, WT_INSERT **, uint32_t);
-static void __wt_free_insert_list(SESSION *, WT_INSERT *);
-static void __wt_free_page_col_fix(SESSION *, WT_PAGE *);
-static void __wt_free_page_col_int(SESSION *, WT_PAGE *);
-static void __wt_free_page_col_rle(SESSION *, WT_PAGE *);
-static void __wt_free_page_col_var(SESSION *, WT_PAGE *);
-static void __wt_free_page_row_int(SESSION *, WT_PAGE *, uint32_t);
-static void __wt_free_page_row_leaf(SESSION *, WT_PAGE *, uint32_t);
-static void __wt_free_update(SESSION *, WT_UPDATE **, uint32_t);
-static void __wt_free_update_list(SESSION *, WT_UPDATE *);
+static void __wt_free_insert(WT_SESSION_IMPL *, WT_INSERT **, uint32_t);
+static void __wt_free_insert_list(WT_SESSION_IMPL *, WT_INSERT *);
+static void __wt_free_page_col_fix(WT_SESSION_IMPL *, WT_PAGE *);
+static void __wt_free_page_col_int(WT_SESSION_IMPL *, WT_PAGE *);
+static void __wt_free_page_col_rle(WT_SESSION_IMPL *, WT_PAGE *);
+static void __wt_free_page_col_var(WT_SESSION_IMPL *, WT_PAGE *);
+static void __wt_free_page_row_int(WT_SESSION_IMPL *, WT_PAGE *, uint32_t);
+static void __wt_free_page_row_leaf(WT_SESSION_IMPL *, WT_PAGE *, uint32_t);
+static void __wt_free_update(WT_SESSION_IMPL *, WT_UPDATE **, uint32_t);
+static void __wt_free_update_list(WT_SESSION_IMPL *, WT_UPDATE *);
 
 /*
  * __wt_page_free --
@@ -25,7 +25,7 @@ static void __wt_free_update_list(SESSION *, WT_UPDATE *);
  */
 void
 __wt_page_free(
-    SESSION *session, WT_PAGE *page, uint32_t addr, uint32_t size)
+    WT_SESSION_IMPL *session, WT_PAGE *page, uint32_t addr, uint32_t size)
 {
 	WT_VERBOSE(S2C(session), WT_VERB_EVICT,
 	    (session, "discard addr %lu/%lu (type %s)",
@@ -112,7 +112,7 @@ __wt_page_free(
  *	Discard a WT_PAGE_COL_FIX page.
  */
 static void
-__wt_free_page_col_fix(SESSION *session, WT_PAGE *page)
+__wt_free_page_col_fix(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
 	/* Free the in-memory index array. */
 	if (page->u.col_leaf.d != NULL)
@@ -129,7 +129,7 @@ __wt_free_page_col_fix(SESSION *session, WT_PAGE *page)
  *	Discard a WT_PAGE_COL_INT page.
  */
 static void
-__wt_free_page_col_int(SESSION *session, WT_PAGE *page)
+__wt_free_page_col_int(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
 	/* Free the subtree-reference array. */
 	if (page->u.col_int.t != NULL)
@@ -141,7 +141,7 @@ __wt_free_page_col_int(SESSION *session, WT_PAGE *page)
  *	Discard a WT_PAGE_COL_RLE page.
  */
 static void
-__wt_free_page_col_rle(SESSION *session, WT_PAGE *page)
+__wt_free_page_col_rle(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
 	/* Free the in-memory index array. */
 	if (page->u.col_leaf.d != NULL)
@@ -158,7 +158,7 @@ __wt_free_page_col_rle(SESSION *session, WT_PAGE *page)
  *	Discard a WT_PAGE_COL_VAR page.
  */
 static void
-__wt_free_page_col_var(SESSION *session, WT_PAGE *page)
+__wt_free_page_col_var(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
 	/* Free the in-memory index array. */
 	if (page->u.col_leaf.d != NULL)
@@ -175,7 +175,7 @@ __wt_free_page_col_var(SESSION *session, WT_PAGE *page)
  *	Discard a WT_PAGE_ROW_INT page.
  */
 static void
-__wt_free_page_row_int(SESSION *session, WT_PAGE *page, uint32_t size)
+__wt_free_page_row_int(WT_SESSION_IMPL *session, WT_PAGE *page, uint32_t size)
 {
 	WT_ROW_REF *rref;
 	uint32_t i;
@@ -198,7 +198,7 @@ __wt_free_page_row_int(SESSION *session, WT_PAGE *page, uint32_t size)
  *	Discard a WT_PAGE_ROW_LEAF page.
  */
 static void
-__wt_free_page_row_leaf(SESSION *session, WT_PAGE *page, uint32_t size)
+__wt_free_page_row_leaf(WT_SESSION_IMPL *session, WT_PAGE *page, uint32_t size)
 {
 	WT_ROW *rip;
 	uint32_t i;
@@ -238,7 +238,7 @@ __wt_free_page_row_leaf(SESSION *session, WT_PAGE *page, uint32_t size)
  */
 static void
 __wt_free_insert(
-    SESSION *session, WT_INSERT **insert_head, uint32_t entries)
+    WT_SESSION_IMPL *session, WT_INSERT **insert_head, uint32_t entries)
 {
 	WT_INSERT **insp;
 
@@ -260,7 +260,7 @@ __wt_free_insert(
  * of a WT_INSERT structure and its associated chain of WT_UPDATE structures.
  */
 static void
-__wt_free_insert_list(SESSION *session, WT_INSERT *ins)
+__wt_free_insert_list(WT_SESSION_IMPL *session, WT_INSERT *ins)
 {
 	WT_INSERT *next;
 
@@ -278,7 +278,7 @@ __wt_free_insert_list(SESSION *session, WT_INSERT *ins)
  */
 static void
 __wt_free_update(
-    SESSION *session, WT_UPDATE **update_head, uint32_t entries)
+    WT_SESSION_IMPL *session, WT_UPDATE **update_head, uint32_t entries)
 {
 	WT_UPDATE **updp;
 
@@ -300,7 +300,7 @@ __wt_free_update(
  *	of a WT_UPDATE structure and its associated data.
  */
 static void
-__wt_free_update_list(SESSION *session, WT_UPDATE *upd)
+__wt_free_update_list(WT_SESSION_IMPL *session, WT_UPDATE *upd)
 {
 	WT_UPDATE *next;
 
diff --git a/src/btree/bt_dump.c b/src/btree/bt_dump.c
index 879f6b14919..28442991eb7 100644
--- a/src/btree/bt_dump.c
+++ b/src/btree/bt_dump.c
@@ -15,11 +15,11 @@ typedef struct {
 	uint64_t fcnt;					/* Progress counter */
 } WT_DSTUFF;
 
-static int  __wt_dump_page(SESSION *, WT_PAGE *, void *);
-static void __wt_dump_page_col_fix(SESSION *, WT_PAGE *, WT_DSTUFF *);
-static int  __wt_dump_page_col_rle(SESSION *, WT_PAGE *, WT_DSTUFF *);
-static int  __wt_dump_page_col_var(SESSION *, WT_PAGE *, WT_DSTUFF *);
-static int  __wt_dump_page_row_leaf(SESSION *, WT_PAGE *, WT_DSTUFF *);
+static int  __wt_dump_page(WT_SESSION_IMPL *, WT_PAGE *, void *);
+static void __wt_dump_page_col_fix(WT_SESSION_IMPL *, WT_PAGE *, WT_DSTUFF *);
+static int  __wt_dump_page_col_rle(WT_SESSION_IMPL *, WT_PAGE *, WT_DSTUFF *);
+static int  __wt_dump_page_col_var(WT_SESSION_IMPL *, WT_PAGE *, WT_DSTUFF *);
+static int  __wt_dump_page_row_leaf(WT_SESSION_IMPL *, WT_PAGE *, WT_DSTUFF *);
 static void __wt_print_byte_string_hex(const uint8_t *, uint32_t, FILE *);
 static void __wt_print_byte_string_nl(const uint8_t *, uint32_t, FILE *);
 
@@ -28,7 +28,7 @@ static void __wt_print_byte_string_nl(const uint8_t *, uint32_t, FILE *);
  *	Db.dump method.
  */
 int
-__wt_btree_dump(SESSION *session, FILE *stream, uint32_t flags)
+__wt_btree_dump(WT_SESSION_IMPL *session, FILE *stream, uint32_t flags)
 {
 	WT_DSTUFF dstuff;
 	int ret;
@@ -68,7 +68,7 @@ __wt_btree_dump(SESSION *session, FILE *stream, uint32_t flags)
  *	Depth-first recursive walk of a btree.
  */
 static int
-__wt_dump_page(SESSION *session, WT_PAGE *page, void *arg)
+__wt_dump_page(WT_SESSION_IMPL *session, WT_PAGE *page, void *arg)
 {
 	WT_DSTUFF *dp;
 
@@ -105,9 +105,9 @@ __wt_dump_page(SESSION *session, WT_PAGE *page, void *arg)
  *	Dump a WT_PAGE_COL_FIX page.
  */
 static void
-__wt_dump_page_col_fix(SESSION *session, WT_PAGE *page, WT_DSTUFF *dp)
+__wt_dump_page_col_fix(WT_SESSION_IMPL *session, WT_PAGE *page, WT_DSTUFF *dp)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_COL *cip;
 	WT_UPDATE *upd;
 	uint32_t i;
@@ -133,9 +133,9 @@ __wt_dump_page_col_fix(SESSION *session, WT_PAGE *page, WT_DSTUFF *dp)
  *	Dump a WT_PAGE_COL_RLE page.
  */
 static int
-__wt_dump_page_col_rle(SESSION *session, WT_PAGE *page, WT_DSTUFF *dp)
+__wt_dump_page_col_rle(WT_SESSION_IMPL *session, WT_PAGE *page, WT_DSTUFF *dp)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	FILE *fp;
 	WT_COL *cip;
 	WT_INSERT *ins;
@@ -181,9 +181,9 @@ __wt_dump_page_col_rle(SESSION *session, WT_PAGE *page, WT_DSTUFF *dp)
  *	Dump a WT_PAGE_COL_VAR page.
  */
 static int
-__wt_dump_page_col_var(SESSION *session, WT_PAGE *page, WT_DSTUFF *dp)
+__wt_dump_page_col_var(WT_SESSION_IMPL *session, WT_PAGE *page, WT_DSTUFF *dp)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_BUF *tmp;
 	WT_COL *cip;
 	WT_CELL *cell;
@@ -235,9 +235,9 @@ err:	__wt_scr_release(&tmp);
  *	Dump a WT_PAGE_ROW_LEAF page.
  */
 static int
-__wt_dump_page_row_leaf(SESSION *session, WT_PAGE *page, WT_DSTUFF *dp)
+__wt_dump_page_row_leaf(WT_SESSION_IMPL *session, WT_PAGE *page, WT_DSTUFF *dp)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_BUF *key_tmp, *value_tmp;
 	WT_CELL *cell;
 	WT_INSERT *ins;
diff --git a/src/btree/bt_evict.c b/src/btree/bt_evict.c
index 04c988aad53..f11097a6fdd 100644
--- a/src/btree/bt_evict.c
+++ b/src/btree/bt_evict.c
@@ -9,20 +9,20 @@
 #include "btree.i"
 
 static inline void __evict_clr(WT_EVICT_LIST *);
-static inline void __evict_req_clr(SESSION *, WT_EVICT_REQ *);
-static inline void __evict_req_set(SESSION *, WT_EVICT_REQ *, int);
+static inline void __evict_req_clr(WT_SESSION_IMPL *, WT_EVICT_REQ *);
+static inline void __evict_req_set(WT_SESSION_IMPL *, WT_EVICT_REQ *, int);
 
-static void __evict_dup_remove(SESSION *);
-static int  __evict_file(SESSION *, WT_EVICT_REQ *);
-static int  __evict_lru(SESSION *);
+static void __evict_dup_remove(WT_SESSION_IMPL *);
+static int  __evict_file(WT_SESSION_IMPL *, WT_EVICT_REQ *);
+static int  __evict_lru(WT_SESSION_IMPL *);
 static int  __evict_lru_cmp(const void *, const void *);
-static void __evict_page(SESSION *);
+static void __evict_page(WT_SESSION_IMPL *);
 static int  __evict_page_cmp(const void *, const void *);
-static int  __evict_request_retry(SESSION *);
-static int  __evict_request_walk(SESSION *);
-static int  __evict_walk(SESSION *);
-static int  __evict_walk_file(SESSION *, u_int);
-static int  __evict_worker(SESSION *);
+static int  __evict_request_retry(WT_SESSION_IMPL *);
+static int  __evict_request_walk(WT_SESSION_IMPL *);
+static int  __evict_walk(WT_SESSION_IMPL *);
+static int  __evict_walk_file(WT_SESSION_IMPL *, u_int);
+static int  __evict_worker(WT_SESSION_IMPL *);
 
 /*
  * Tuning constants -- I hesitate to call this tuning, but we should review some
@@ -66,7 +66,7 @@ __evict_clr(WT_EVICT_LIST *e)
  *	Set an entry in the eviction request list.
  */
 static inline void
-__evict_req_set(SESSION *session, WT_EVICT_REQ *r, int close_method)
+__evict_req_set(WT_SESSION_IMPL *session, WT_EVICT_REQ *r, int close_method)
 {
 	r->close_method = close_method;
 	WT_ASSERT(session, r->retry == NULL);
@@ -84,7 +84,7 @@ __evict_req_set(SESSION *session, WT_EVICT_REQ *r, int close_method)
  *	Set an entry in the eviction request list.
  */
 static inline void
-__evict_req_clr(SESSION *session, WT_EVICT_REQ *r)
+__evict_req_clr(WT_SESSION_IMPL *session, WT_EVICT_REQ *r)
 {
 	if (r->retry != NULL)
 		__wt_free(session, r->retry);
@@ -99,9 +99,9 @@ __evict_req_clr(SESSION *session, WT_EVICT_REQ *r)
  *	See if the eviction server thread needs to be awakened.
  */
 void
-__wt_workq_evict_server(CONNECTION *conn, int force)
+__wt_workq_evict_server(WT_CONNECTION_IMPL *conn, int force)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	WT_CACHE *cache;
 	uint64_t bytes_inuse, bytes_max;
 
@@ -140,7 +140,7 @@ __wt_workq_evict_server(CONNECTION *conn, int force)
  *	or closed.
  */
 int
-__wt_evict_file_serial_func(SESSION *session)
+__wt_evict_file_serial_func(WT_SESSION_IMPL *session)
 {
 	WT_CACHE *cache;
 	WT_EVICT_REQ *er, *er_end;
@@ -167,8 +167,8 @@ __wt_evict_file_serial_func(SESSION *session)
 void *
 __wt_cache_evict_server(void *arg)
 {
-	CONNECTION *conn;
-	SESSION *session;
+	WT_CONNECTION_IMPL *conn;
+	WT_SESSION_IMPL *session;
 	WT_SESSION *wt_session;
 	WT_CACHE *cache;
 	WT_EVICT_REQ *er, *er_end;
@@ -191,7 +191,7 @@ __wt_cache_evict_server(void *arg)
 	session = &conn->default_session;
 	wt_session = NULL;
 	WT_ERR(conn->iface.open_session(&conn->iface, NULL, NULL, &wt_session));
-	session = (SESSION *)wt_session;
+	session = (WT_SESSION_IMPL *)wt_session;
 	/*
 	 * Don't close this session during WT_CONNECTION->close: we do it
 	 * before the thread completes.
@@ -244,9 +244,9 @@ err:		__wt_err(session, ret, "cache eviction server error");
  *	The exit flag is set, wake the eviction server to exit.
  */
 void
-__wt_workq_evict_server_exit(CONNECTION *conn)
+__wt_workq_evict_server_exit(WT_CONNECTION_IMPL *conn)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	WT_CACHE *cache;
 
 	session = &conn->default_session;
@@ -260,7 +260,7 @@ __wt_workq_evict_server_exit(CONNECTION *conn)
  *	Evict pages from memory.
  */
 static int
-__evict_worker(SESSION *session)
+__evict_worker(WT_SESSION_IMPL *session)
 {
 	WT_CACHE *cache;
 	uint64_t bytes_start, bytes_inuse, bytes_max;
@@ -329,9 +329,9 @@ __evict_worker(SESSION *session)
  *	Walk the eviction request queue.
  */
 static int
-__evict_request_walk(SESSION *session)
+__evict_request_walk(WT_SESSION_IMPL *session)
 {
-	SESSION *request_session;
+	WT_SESSION_IMPL *request_session;
 	WT_CACHE *cache;
 	WT_EVICT_REQ *er, *er_end;
 	int ret;
@@ -339,10 +339,10 @@ __evict_request_walk(SESSION *session)
 	cache = S2C(session)->cache;
 
 	/*
-	 * Walk the eviction request queue, looking for sync or close requests
-	 * (defined by a valid SESSION handle).  If we find a request, perform
-	 * it, flush the result and clear the request slot, then wake up the
-	 * requesting thread.
+         * Walk the eviction request queue, looking for sync or close requests
+         * (defined by a valid WT_SESSION_IMPL handle).  If we find a request,
+         * perform it, flush the result and clear the request slot, then wake
+         * up the requesting thread.
 	 */
 	WT_EVICT_REQ_FOREACH(er, er_end, cache) {
 		if ((request_session = er->session) == NULL)
@@ -354,7 +354,7 @@ __evict_request_walk(SESSION *session)
 		 */
 		memset(cache->evict, 0, cache->evict_allocated);
 
-		/* Reference the correct BTREE handle. */
+		/* Reference the correct WT_BTREE handle. */
 		WT_SET_BTREE_IN_SESSION(session, request_session->btree);
 
 		ret = __evict_file(session, er);
@@ -379,9 +379,9 @@ __evict_request_walk(SESSION *session)
  *	Flush pages for a specific file as part of a close/sync operation.
  */
 static int
-__evict_file(SESSION *session, WT_EVICT_REQ *er)
+__evict_file(WT_SESSION_IMPL *session, WT_EVICT_REQ *er)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_PAGE *page;
 	uint32_t flags;
 	int ret;
@@ -443,9 +443,9 @@ err:	/* End the walk cleanly. */
  *	Retry an eviction request.
  */
 static int
-__evict_request_retry(SESSION *session)
+__evict_request_retry(WT_SESSION_IMPL *session)
 {
-	SESSION *request_session;
+	WT_SESSION_IMPL *request_session;
 	WT_CACHE *cache;
 	WT_EVICT_REQ *er, *er_end;
 	uint32_t i, flags;
@@ -470,7 +470,7 @@ __evict_request_retry(SESSION *session)
 		 */
 		memset(cache->evict, 0, cache->evict_allocated);
 
-		/* Reference the correct BTREE handle. */
+		/* Reference the correct WT_BTREE handle. */
 		request_session = er->session;
 		WT_SET_BTREE_IN_SESSION(session, request_session->btree);
 
@@ -510,7 +510,7 @@ __evict_request_retry(SESSION *session)
  *	Evict pages from the cache based on their read generation.
  */
 static int
-__evict_lru(SESSION *session)
+__evict_lru(WT_SESSION_IMPL *session)
 {
 	/* Get some more pages to consider for eviction. */
 	WT_RET(__evict_walk(session));
@@ -529,10 +529,10 @@ __evict_lru(SESSION *session)
  *	Fill in the array by walking the next set of pages.
  */
 static int
-__evict_walk(SESSION *session)
+__evict_walk(WT_SESSION_IMPL *session)
 {
-	CONNECTION *conn;
-	BTREE *btree;
+	WT_CONNECTION_IMPL *conn;
+	WT_BTREE *btree;
 	WT_CACHE *cache;
 	u_int elem, i;
 	int ret;
@@ -561,7 +561,7 @@ __evict_walk(SESSION *session)
 			if (F_ISSET(btree, WT_BTREE_NO_EVICTION))
 				continue;
 
-			/* Reference the correct BTREE handle. */
+			/* Reference the correct WT_BTREE handle. */
 			WT_SET_BTREE_IN_SESSION(session, btree);
 
 			WT_ERR(__evict_walk_file(session, i));
@@ -577,9 +577,9 @@ err:	__wt_unlock(session, conn->mtx);
  *	Get a few page eviction candidates from a single underlying file.
  */
 static int
-__evict_walk_file(SESSION *session, u_int slot)
+__evict_walk_file(WT_SESSION_IMPL *session, u_int slot)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_CACHE *cache;
 	WT_PAGE *page;
 	int i, restarted_once;
@@ -635,7 +635,7 @@ walk:		WT_RET(__wt_walk_begin(
  *	Discard duplicates from the list of pages we collected.
  */
 static void
-__evict_dup_remove(SESSION *session)
+__evict_dup_remove(WT_SESSION_IMPL *session)
 {
 	WT_CACHE *cache;
 	WT_EVICT_LIST *evict;
@@ -683,7 +683,7 @@ __evict_dup_remove(SESSION *session)
  *	Reconcile and discard cache pages.
  */
 static void
-__evict_page(SESSION *session)
+__evict_page(WT_SESSION_IMPL *session)
 {
 	WT_CACHE *cache;
 	WT_EVICT_LIST *evict;
@@ -700,7 +700,7 @@ __evict_page(SESSION *session)
 		if ((page = evict->page) == NULL)
 			continue;
 
-		/* Reference the correct BTREE handle. */
+		/* Reference the correct WT_BTREE handle. */
 		WT_SET_BTREE_IN_SESSION(session, evict->btree);
 
 		/*
diff --git a/src/btree/bt_handle.c b/src/btree/bt_handle.c
index e4d3c3fa5b3..f845194e944 100644
--- a/src/btree/bt_handle.c
+++ b/src/btree/bt_handle.c
@@ -7,17 +7,18 @@
 
 #include "wt_internal.h"
 
-static int __btree_conf(SESSION *);
-static int __btree_init(SESSION *, const char *);
-static int __btree_page_sizes(SESSION *);
-static int __btree_type(SESSION *);
+static int __btree_conf(WT_SESSION_IMPL *);
+static int __btree_init(WT_SESSION_IMPL *, const char *);
+static int __btree_page_sizes(WT_SESSION_IMPL *);
+static int __btree_type(WT_SESSION_IMPL *);
 
 /*
  * __wt_btree_create --
  *	Create a Btree.
  */
 int
-__wt_btree_create(SESSION *session, const char *name, const char *config)
+__wt_btree_create(
+    WT_SESSION_IMPL *session, const char *name, const char *config)
 {
 	WT_FH *fh;
 	int ret;
@@ -48,30 +49,30 @@ __wt_btree_create(SESSION *session, const char *name, const char *config)
  *	Open a Btree.
  */
 int
-__wt_btree_open(SESSION *session, const char *name, uint32_t flags)
+__wt_btree_open(WT_SESSION_IMPL *session, const char *name, uint32_t flags)
 {
-	CONNECTION *conn;
-	BTREE *btree;
+	WT_CONNECTION_IMPL *conn;
+	WT_BTREE *btree;
 	WT_PAGE *page;
 
 	conn = S2C(session);
 	btree = session->btree;
 
-	/* Create the BTREE structure. */
+	/* Create the WT_BTREE structure. */
 	WT_RET(__wt_calloc_def(session, 1, &btree));
 	btree->flags = flags;
 	btree->conn = conn;
 	session->btree = btree;
 
-	/* Initialize the BTREE structure. */
+	/* Initialize the WT_BTREE structure. */
 	WT_RET(__btree_init(session, name));
 
 	/* Open the underlying file handle. */
 	WT_RET(__wt_open(session, name, 0666, 1, &btree->fh));
 
 	/*
-	 * Read in the file's metadata, configure the BTREE structure based on
-	 * the configuration string, read in the free-list.
+         * Read in the file's metadata, configure the WT_BTREE structure based
+         * on the configuration string, read in the free-list.
 	 *
 	 * XXX Take extra care with this if WT_BTREE_VERIFY is set?
 	 */
@@ -130,12 +131,12 @@ __wt_btree_open(SESSION *session, const char *name, uint32_t flags)
 
 /*
  * __btree_init --
- *	Initialize the BTREE structure, after an zero-filled allocation.
+ *	Initialize the WT_BTREE structure, after an zero-filled allocation.
  */
 static int
-__btree_init(SESSION *session, const char *name)
+__btree_init(WT_SESSION_IMPL *session, const char *name)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 
 	btree = session->btree;
 
@@ -161,10 +162,10 @@ __btree_init(SESSION *session, const char *name)
  *	Close a Btree.
  */
 int
-__wt_btree_close(SESSION *session)
+__wt_btree_close(WT_SESSION_IMPL *session)
 {
-	BTREE *btree;
-	CONNECTION *conn;
+	WT_BTREE *btree;
+	WT_CONNECTION_IMPL *conn;
 	int ret;
 
 	btree = session->btree;
@@ -213,7 +214,7 @@ __wt_btree_close(SESSION *session)
  *	Configure the btree and verify the configuration relationships.
  */
 static int
-__btree_conf(SESSION *session)
+__btree_conf(WT_SESSION_IMPL *session)
 {
 	/* File type. */
 	WT_RET(__btree_type(session));
@@ -232,11 +233,11 @@ __btree_conf(SESSION *session)
  *	Figure out the database type.
  */
 static int
-__btree_type(SESSION *session)
+__btree_type(WT_SESSION_IMPL *session)
 {
 	const char *config;
 	char *endp, t;
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_CONFIG_ITEM cval;
 
 	btree = session->btree;
@@ -276,9 +277,9 @@ __btree_type(SESSION *session)
  *	Verify the page sizes.
  */
 static int
-__btree_page_sizes(SESSION *session)
+__btree_page_sizes(WT_SESSION_IMPL *session)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_CONFIG_ITEM cval;
 	const char *config;
 
diff --git a/src/btree/bt_huffman.c b/src/btree/bt_huffman.c
index 32a206c9d54..0a6c01a7194 100644
--- a/src/btree/bt_huffman.c
+++ b/src/btree/bt_huffman.c
@@ -124,7 +124,7 @@ static const struct __wt_huffman_table __wt_huffman_nytenglish[] = {
 	/*  ~  */	{ 0x7e,       1 }
 };
 
-static int __wt_huffman_read(SESSION *,
+static int __wt_huffman_read(WT_SESSION_IMPL *,
     WT_CONFIG_ITEM *, struct __wt_huffman_table **, u_int *, u_int *);
 
 /*
@@ -132,9 +132,9 @@ static int __wt_huffman_read(SESSION *,
  *	Configure Huffman encoding for the tree.
  */
 int
-__wt_btree_huffman_open(SESSION *session)
+__wt_btree_huffman_open(WT_SESSION_IMPL *session)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	u_int entries, numbytes;
 	struct __wt_huffman_table *table;
 	WT_CONFIG_ITEM key_conf, value_conf;
@@ -226,7 +226,7 @@ __wt_btree_huffman_open(SESSION *session)
  *	Read a Huffman table from a file.
  */
 static int
-__wt_huffman_read(SESSION *session, WT_CONFIG_ITEM *ip,
+__wt_huffman_read(WT_SESSION_IMPL *session, WT_CONFIG_ITEM *ip,
     struct __wt_huffman_table **tablep, u_int *entriesp, u_int *numbytesp)
 {
 	struct __wt_huffman_table *table, *tp;
@@ -333,9 +333,9 @@ err:	if (ret == 0)
  *	Close the Huffman tables.
  */
 void
-__wt_btree_huffman_close(SESSION *session)
+__wt_btree_huffman_close(WT_SESSION_IMPL *session)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 
 	btree = session->btree;
 
diff --git a/src/btree/bt_ovfl.c b/src/btree/bt_ovfl.c
index a0b793b1c74..79aaf49fdd3 100644
--- a/src/btree/bt_ovfl.c
+++ b/src/btree/bt_ovfl.c
@@ -12,10 +12,10 @@
  *	Read an overflow item from the disk.
  */
 int
-__wt_ovfl_in(SESSION *session, WT_OFF *ovfl, WT_BUF *store)
+__wt_ovfl_in(WT_SESSION_IMPL *session, WT_OFF *ovfl, WT_BUF *store)
 {
-	BTREE *btree;
-	CONNECTION *conn;
+	WT_BTREE *btree;
+	WT_CONNECTION_IMPL *conn;
 
 	conn = S2C(session);
 	btree = session->btree;
diff --git a/src/btree/bt_page.c b/src/btree/bt_page.c
index f96b56c68b0..4ec18d97c9e 100644
--- a/src/btree/bt_page.c
+++ b/src/btree/bt_page.c
@@ -9,12 +9,12 @@
 #include "btree.i"
 #include "cell.i"
 
-static int __wt_page_inmem_col_fix(SESSION *, WT_PAGE *);
-static int __wt_page_inmem_col_int(SESSION *, WT_PAGE *);
-static int __wt_page_inmem_col_rle(SESSION *, WT_PAGE *);
-static int __wt_page_inmem_col_var(SESSION *, WT_PAGE *);
-static int __wt_page_inmem_row_int(SESSION *, WT_PAGE *);
-static int __wt_page_inmem_row_leaf(SESSION *, WT_PAGE *);
+static int __wt_page_inmem_col_fix(WT_SESSION_IMPL *, WT_PAGE *);
+static int __wt_page_inmem_col_int(WT_SESSION_IMPL *, WT_PAGE *);
+static int __wt_page_inmem_col_rle(WT_SESSION_IMPL *, WT_PAGE *);
+static int __wt_page_inmem_col_var(WT_SESSION_IMPL *, WT_PAGE *);
+static int __wt_page_inmem_row_int(WT_SESSION_IMPL *, WT_PAGE *);
+static int __wt_page_inmem_row_leaf(WT_SESSION_IMPL *, WT_PAGE *);
 
 /*
  * __wt_page_in --
@@ -22,7 +22,8 @@ static int __wt_page_inmem_row_leaf(SESSION *, WT_PAGE *);
  *	read it from the disk and build an in-memory version.
  */
 int
-__wt_page_in_func(SESSION *session, WT_PAGE *parent, WT_REF *ref, int dsk_verify
+__wt_page_in_func(
+    WT_SESSION_IMPL *session, WT_PAGE *parent, WT_REF *ref, int dsk_verify
 #ifdef HAVE_DIAGNOSTIC
     , const char *file, int line
 #endif
@@ -76,7 +77,7 @@ __wt_page_in_func(SESSION *session, WT_PAGE *parent, WT_REF *ref, int dsk_verify
  *	Build in-memory page information.
  */
 int
-__wt_page_inmem(SESSION *session,
+__wt_page_inmem(WT_SESSION_IMPL *session,
     WT_PAGE *parent, WT_REF *parent_ref, WT_PAGE_DISK *dsk, WT_PAGE **pagep)
 {
 	WT_PAGE *page;
@@ -140,9 +141,9 @@ err:	if (page != NULL)
  *	Build in-memory index for fixed-length column-store leaf pages.
  */
 static int
-__wt_page_inmem_col_fix(SESSION *session, WT_PAGE *page)
+__wt_page_inmem_col_fix(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_COL *cip;
 	WT_PAGE_DISK *dsk;
 	uint32_t i;
@@ -175,7 +176,7 @@ __wt_page_inmem_col_fix(SESSION *session, WT_PAGE *page)
  *	Build in-memory index for column-store internal pages.
  */
 static int
-__wt_page_inmem_col_int(SESSION *session, WT_PAGE *page)
+__wt_page_inmem_col_int(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
 	WT_COL_REF *cref;
 	WT_OFF_RECORD *off_record;
@@ -213,9 +214,9 @@ __wt_page_inmem_col_int(SESSION *session, WT_PAGE *page)
  *	leaf pages.
  */
 static int
-__wt_page_inmem_col_rle(SESSION *session, WT_PAGE *page)
+__wt_page_inmem_col_rle(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_COL *cip;
 	WT_PAGE_DISK *dsk;
 	uint32_t i;
@@ -249,7 +250,7 @@ __wt_page_inmem_col_rle(SESSION *session, WT_PAGE *page)
  *	column-store trees.
  */
 static int
-__wt_page_inmem_col_var(SESSION *session, WT_PAGE *page)
+__wt_page_inmem_col_var(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
 	WT_COL *cip;
 	WT_CELL *cell;
@@ -283,7 +284,7 @@ __wt_page_inmem_col_var(SESSION *session, WT_PAGE *page)
  *	Build in-memory index for row-store internal pages.
  */
 static int
-__wt_page_inmem_row_int(SESSION *session, WT_PAGE *page)
+__wt_page_inmem_row_int(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
 	WT_CELL *cell;
 	WT_OFF off;
@@ -340,7 +341,7 @@ __wt_page_inmem_row_int(SESSION *session, WT_PAGE *page)
  *	Build in-memory index for row-store leaf pages.
  */
 static int
-__wt_page_inmem_row_leaf(SESSION *session, WT_PAGE *page)
+__wt_page_inmem_row_leaf(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
 	WT_CELL *cell;
 	WT_PAGE_DISK *dsk;
diff --git a/src/btree/bt_read.c b/src/btree/bt_read.c
index b0350b41ca4..eb942537f3b 100644
--- a/src/btree/bt_read.c
+++ b/src/btree/bt_read.c
@@ -8,11 +8,11 @@
 #include "wt_internal.h"
 #include "btree.i"
 
-static inline void
-    __cache_read_req_set(SESSION *, WT_READ_REQ *, WT_PAGE *, WT_REF *, int);
+static inline void __cache_read_req_set(
+        WT_SESSION_IMPL *, WT_READ_REQ *, WT_PAGE *, WT_REF *, int);
 static inline void __cache_read_req_clr(WT_READ_REQ *);
 
-static int __cache_read(SESSION *, WT_PAGE *, WT_REF *, int);
+static int __cache_read(WT_SESSION_IMPL *, WT_PAGE *, WT_REF *, int);
 
 #define	WT_READ_REQ_FOREACH(rr, rr_end, cache)				\
 	for ((rr) = (cache)->read_request,				\
@@ -20,7 +20,7 @@ static int __cache_read(SESSION *, WT_PAGE *, WT_REF *, int);
 	    (rr) < (rr_end); ++(rr))
 
 static inline void
-__cache_read_req_set(SESSION *session,
+__cache_read_req_set(WT_SESSION_IMPL *session,
     WT_READ_REQ *rr, WT_PAGE *parent, WT_REF *ref, int dsk_verify)
 {
 	rr->parent = parent;
@@ -44,7 +44,7 @@ __cache_read_req_clr(WT_READ_REQ *rr)
  *	See if the read server thread needs to be awakened.
  */
 void
-__wt_workq_read_server(CONNECTION *conn, int force)
+__wt_workq_read_server(WT_CONNECTION_IMPL *conn, int force)
 {
 	WT_CACHE *cache;
 	uint64_t bytes_inuse, bytes_max;
@@ -94,7 +94,7 @@ __wt_workq_read_server(CONNECTION *conn, int force)
  *	allocation or a read.
  */
 int
-__wt_cache_read_serial_func(SESSION *session)
+__wt_cache_read_serial_func(WT_SESSION_IMPL *session)
 {
 	WT_CACHE *cache;
 	WT_PAGE *parent;
@@ -124,8 +124,8 @@ __wt_cache_read_serial_func(SESSION *session)
 void *
 __wt_cache_read_server(void *arg)
 {
-	CONNECTION *conn;
-	SESSION *session, *request_session;
+	WT_CONNECTION_IMPL *conn;
+	WT_SESSION_IMPL *session, *request_session;
 	WT_CACHE *cache;
 	WT_READ_REQ *rr, *rr_end;
 	WT_SESSION *wt_session;
@@ -151,7 +151,7 @@ __wt_cache_read_server(void *arg)
 		__wt_err(session, ret, "cache read server error");
 		return (NULL);
 	}
-	session = (SESSION *)wt_session;
+	session = (WT_SESSION_IMPL *)wt_session;
 	/*
 	 * Don't close this session during WT_CONNECTION->close: we do it
 	 * before the thread completes.
@@ -170,9 +170,9 @@ __wt_cache_read_server(void *arg)
 
 		/*
 		 * Walk the read-request queue, looking for reads (defined by
-		 * a valid SESSION handle).  If we find a read request, perform
-		 * it, flush the result and clear the request slot, then wake
-		 * up the requesting thread.
+                 * a valid WT_SESSION_IMPL handle).  If we find a read request,
+                 * perform it, flush the result and clear the request slot,
+                 * then wake up the requesting thread.
 		 */
 		do {
 			didwork = 0;
@@ -183,7 +183,7 @@ __wt_cache_read_server(void *arg)
 					continue;
 				didwork = 1;
 
-				/* Reference the correct BTREE handle. */
+				/* Reference the correct WT_BTREE handle. */
 				WT_SET_BTREE_IN_SESSION(
 				    session, request_session->btree);
 
@@ -213,9 +213,9 @@ __wt_cache_read_server(void *arg)
  *	The exit flag is set, wake the read server to exit.
  */
 void
-__wt_workq_read_server_exit(CONNECTION *conn)
+__wt_workq_read_server_exit(WT_CONNECTION_IMPL *conn)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	WT_CACHE *cache;
 
 	session = &conn->default_session;
@@ -229,7 +229,8 @@ __wt_workq_read_server_exit(CONNECTION *conn)
  *	Read a page from the file.
  */
 static int
-__cache_read(SESSION *session, WT_PAGE *parent, WT_REF *ref, int dsk_verify)
+__cache_read(
+    WT_SESSION_IMPL *session, WT_PAGE *parent, WT_REF *ref, int dsk_verify)
 {
 	WT_PAGE_DISK *dsk;
 	uint32_t addr, size;
diff --git a/src/btree/bt_reconcile.c b/src/btree/bt_reconcile.c
index 30451dc9aae..147d5cb579b 100644
--- a/src/btree/bt_reconcile.c
+++ b/src/btree/bt_reconcile.c
@@ -192,59 +192,59 @@ typedef struct {
 	int	key_prefix_compress;	/* If can prefix-compress next key */
 } WT_RECONCILE;
 
-static inline void __rec_copy_incr(SESSION *, WT_RECONCILE *, WT_KV *);
-static inline int  __rec_discard_add_ovfl(SESSION *, WT_CELL *);
-static inline void __rec_incr(SESSION *, WT_RECONCILE *, uint32_t);
+static inline void __rec_copy_incr(WT_SESSION_IMPL *, WT_RECONCILE *, WT_KV *);
+static inline int  __rec_discard_add_ovfl(WT_SESSION_IMPL *, WT_CELL *);
+static inline void __rec_incr(WT_SESSION_IMPL *, WT_RECONCILE *, uint32_t);
 static inline void __rec_prefix_key_update(WT_RECONCILE *);
 
 static int  __hazard_bsearch_cmp(const void *, const void *);
-static void __hazard_copy(SESSION *);
-static int  __hazard_exclusive(SESSION *, WT_REF *);
+static void __hazard_copy(WT_SESSION_IMPL *);
+static int  __hazard_exclusive(WT_SESSION_IMPL *, WT_REF *);
 static int  __hazard_qsort_cmp(const void *, const void *);
 static uint32_t
-	    __rec_allocation_size(SESSION *, WT_BUF *, uint8_t *);
-static int  __rec_cell_build_key(SESSION *, const void *, uint32_t);
-static int  __rec_cell_build_ovfl(SESSION *, WT_KV *, u_int);
-static int  __rec_cell_build_val(SESSION *, void *, uint32_t);
-static int  __rec_col_fix(SESSION *, WT_PAGE *);
-static int  __rec_col_fix_bulk(SESSION *, WT_PAGE *);
-static int  __rec_col_int(SESSION *, WT_PAGE *);
-static int  __rec_col_merge(SESSION *, WT_PAGE *);
-static int  __rec_col_rle(SESSION *, WT_PAGE *);
-static int  __rec_col_rle_bulk(SESSION *, WT_PAGE *);
-static int  __rec_col_split(SESSION *, WT_PAGE **, WT_PAGE *);
-static int  __rec_col_var(SESSION *, WT_PAGE *);
-static int  __rec_col_var_bulk(SESSION *, WT_PAGE *);
-static int  __rec_discard_add(SESSION *, WT_PAGE *, uint32_t, uint32_t);
-static int  __rec_discard_evict(SESSION *);
+	    __rec_allocation_size(WT_SESSION_IMPL *, WT_BUF *, uint8_t *);
+static int  __rec_cell_build_key(WT_SESSION_IMPL *, const void *, uint32_t);
+static int  __rec_cell_build_ovfl(WT_SESSION_IMPL *, WT_KV *, u_int);
+static int  __rec_cell_build_val(WT_SESSION_IMPL *, void *, uint32_t);
+static int  __rec_col_fix(WT_SESSION_IMPL *, WT_PAGE *);
+static int  __rec_col_fix_bulk(WT_SESSION_IMPL *, WT_PAGE *);
+static int  __rec_col_int(WT_SESSION_IMPL *, WT_PAGE *);
+static int  __rec_col_merge(WT_SESSION_IMPL *, WT_PAGE *);
+static int  __rec_col_rle(WT_SESSION_IMPL *, WT_PAGE *);
+static int  __rec_col_rle_bulk(WT_SESSION_IMPL *, WT_PAGE *);
+static int  __rec_col_split(WT_SESSION_IMPL *, WT_PAGE **, WT_PAGE *);
+static int  __rec_col_var(WT_SESSION_IMPL *, WT_PAGE *);
+static int  __rec_col_var_bulk(WT_SESSION_IMPL *, WT_PAGE *);
+static int  __rec_discard_add(WT_SESSION_IMPL *, WT_PAGE *, uint32_t, uint32_t);
+static int  __rec_discard_evict(WT_SESSION_IMPL *);
 static void __rec_discard_init(WT_RECONCILE *);
-static int  __rec_imref_add(SESSION *, WT_REF *);
+static int  __rec_imref_add(WT_SESSION_IMPL *, WT_REF *);
 static int  __rec_imref_bsearch_cmp(const void *, const void *);
-static int  __rec_imref_fixup(SESSION *, WT_PAGE *);
+static int  __rec_imref_fixup(WT_SESSION_IMPL *, WT_PAGE *);
 static void __rec_imref_init(WT_RECONCILE *);
 static int  __rec_imref_qsort_cmp(const void *, const void *);
-static int  __rec_init(SESSION *, uint32_t);
-static int  __rec_ovfl_delete(SESSION *, WT_PAGE *);
-static int  __rec_parent_update(
-		SESSION *, WT_PAGE *, WT_PAGE *, uint32_t, uint32_t, uint32_t);
-static void __rec_parent_update_clean(SESSION *, WT_PAGE *);
-static int  __rec_row_int(SESSION *, WT_PAGE *);
-static int  __rec_row_leaf(SESSION *, WT_PAGE *, uint32_t);
-static int  __rec_row_leaf_insert(SESSION *, WT_INSERT *);
-static int  __rec_row_merge(SESSION *, WT_PAGE *);
-static int  __rec_row_split(SESSION *, WT_PAGE **, WT_PAGE *);
-static int  __rec_split(SESSION *);
-static int  __rec_split_finish(SESSION *);
-static int  __rec_split_fixup(SESSION *);
+static int  __rec_init(WT_SESSION_IMPL *, uint32_t);
+static int  __rec_ovfl_delete(WT_SESSION_IMPL *, WT_PAGE *);
+static int  __rec_parent_update(WT_SESSION_IMPL *,
+                WT_PAGE *, WT_PAGE *, uint32_t, uint32_t, uint32_t);
+static void __rec_parent_update_clean(WT_SESSION_IMPL *, WT_PAGE *);
+static int  __rec_row_int(WT_SESSION_IMPL *, WT_PAGE *);
+static int  __rec_row_leaf(WT_SESSION_IMPL *, WT_PAGE *, uint32_t);
+static int  __rec_row_leaf_insert(WT_SESSION_IMPL *, WT_INSERT *);
+static int  __rec_row_merge(WT_SESSION_IMPL *, WT_PAGE *);
+static int  __rec_row_split(WT_SESSION_IMPL *, WT_PAGE **, WT_PAGE *);
+static int  __rec_split(WT_SESSION_IMPL *);
+static int  __rec_split_finish(WT_SESSION_IMPL *);
+static int  __rec_split_fixup(WT_SESSION_IMPL *);
 static int  __rec_split_init(
-		SESSION *, WT_PAGE *, uint64_t, uint32_t, uint32_t);
-static int  __rec_split_write(SESSION *, WT_BUF *, void *);
-static int  __rec_subtree(SESSION *, WT_PAGE *);
-static int  __rec_subtree_col(SESSION *, WT_PAGE *);
-static void __rec_subtree_col_clear(SESSION *, WT_PAGE *);
-static int  __rec_subtree_row(SESSION *, WT_PAGE *);
-static void __rec_subtree_row_clear(SESSION *, WT_PAGE *);
-static int  __rec_wrapup(SESSION *, WT_PAGE *);
+		WT_SESSION_IMPL *, WT_PAGE *, uint64_t, uint32_t, uint32_t);
+static int  __rec_split_write(WT_SESSION_IMPL *, WT_BUF *, void *);
+static int  __rec_subtree(WT_SESSION_IMPL *, WT_PAGE *);
+static int  __rec_subtree_col(WT_SESSION_IMPL *, WT_PAGE *);
+static void __rec_subtree_col_clear(WT_SESSION_IMPL *, WT_PAGE *);
+static int  __rec_subtree_row(WT_SESSION_IMPL *, WT_PAGE *);
+static void __rec_subtree_row_clear(WT_SESSION_IMPL *, WT_PAGE *);
+static int  __rec_wrapup(WT_SESSION_IMPL *, WT_PAGE *);
 
 /*
  * When discarding a page, we discard a number of things: pages merged into the
@@ -256,7 +256,7 @@ static int  __rec_wrapup(SESSION *, WT_PAGE *);
 #define	__rec_discard_add_page(session, page)				\
 	__rec_discard_add(session, page, WT_PADDR(page), WT_PSIZE(page))
 static inline int
-__rec_discard_add_ovfl(SESSION *session, WT_CELL *cell)
+__rec_discard_add_ovfl(WT_SESSION_IMPL *session, WT_CELL *cell)
 {
 	WT_OFF ovfl;
 
@@ -272,9 +272,9 @@ __rec_discard_add_ovfl(SESSION *session, WT_CELL *cell)
  *	Initialize the reconciliation structure.
  */
 static int
-__rec_init(SESSION *session, uint32_t flags)
+__rec_init(WT_SESSION_IMPL *session, uint32_t flags)
 {
-	CONNECTION *conn;
+	WT_CONNECTION_IMPL *conn;
 	WT_RECONCILE *r;
 
 	/* Allocate a reconciliation structure if we don't already have one. */
@@ -320,7 +320,7 @@ __rec_init(SESSION *session, uint32_t flags)
  *	Clean up the reconciliation structure.
  */
 void
-__wt_rec_destroy(SESSION *session)
+__wt_rec_destroy(WT_SESSION_IMPL *session)
 {
 	WT_RECONCILE *r;
 	WT_SPLIT *spl;
@@ -364,7 +364,7 @@ __wt_rec_destroy(SESSION *session)
  *	Copy a key/value cell and buffer pair onto a page.
  */
 static inline void
-__rec_copy_incr(SESSION *session, WT_RECONCILE *r, WT_KV *kv)
+__rec_copy_incr(WT_SESSION_IMPL *session, WT_RECONCILE *r, WT_KV *kv)
 {
 	uint32_t len;
 	uint8_t *p, *t;
@@ -394,7 +394,7 @@ __rec_copy_incr(SESSION *session, WT_RECONCILE *r, WT_KV *kv)
  *	Update the memory tracking structure for a new entry.
  */
 static inline void
-__rec_incr(SESSION *session, WT_RECONCILE *r, uint32_t size)
+__rec_incr(WT_SESSION_IMPL *session, WT_RECONCILE *r, uint32_t size)
 {
 	/*
 	 * The buffer code is fragile and prone to off-by-one errors --
@@ -415,9 +415,9 @@ __rec_incr(SESSION *session, WT_RECONCILE *r, uint32_t size)
  * (the page size can either grow or shrink), and zero out unused bytes.
  */
 static inline uint32_t
-__rec_allocation_size(SESSION *session, WT_BUF *buf, uint8_t *end)
+__rec_allocation_size(WT_SESSION_IMPL *session, WT_BUF *buf, uint8_t *end)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	uint32_t alloc_len, current_len, write_len;
 
 	btree = session->btree;
@@ -444,9 +444,9 @@ __rec_allocation_size(SESSION *session, WT_BUF *buf, uint8_t *end)
  */
 int
 __wt_page_reconcile(
-    SESSION *session, WT_PAGE *page, uint32_t slvg_skip, uint32_t flags)
+    WT_SESSION_IMPL *session, WT_PAGE *page, uint32_t slvg_skip, uint32_t flags)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_CACHE *cache;
 	int ret;
 
@@ -586,7 +586,7 @@ __wt_page_reconcile(
  *	Get exclusive access to a subtree for reconciliation.
  */
 static int
-__rec_subtree(SESSION *session, WT_PAGE *page)
+__rec_subtree(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
 	WT_RECONCILE *r;
 	int ret;
@@ -667,7 +667,7 @@ __rec_subtree(SESSION *session, WT_PAGE *page)
  *	pages.
  */
 static int
-__rec_subtree_col(SESSION *session, WT_PAGE *parent)
+__rec_subtree_col(WT_SESSION_IMPL *session, WT_PAGE *parent)
 {
 	WT_COL_REF *cref;
 	WT_PAGE *page;
@@ -769,7 +769,7 @@ __rec_subtree_col(SESSION *session, WT_PAGE *parent)
  *	isn't possible.
  */
 static void
-__rec_subtree_col_clear(SESSION *session, WT_PAGE *parent)
+__rec_subtree_col_clear(WT_SESSION_IMPL *session, WT_PAGE *parent)
 {
 	WT_COL_REF *cref;
 	WT_PAGE *page;
@@ -793,7 +793,7 @@ __rec_subtree_col_clear(SESSION *session, WT_PAGE *parent)
  *	pages.
  */
 static int
-__rec_subtree_row(SESSION *session, WT_PAGE *parent)
+__rec_subtree_row(WT_SESSION_IMPL *session, WT_PAGE *parent)
 {
 	WT_PAGE *page;
 	WT_RECONCILE *r;
@@ -894,7 +894,7 @@ __rec_subtree_row(SESSION *session, WT_PAGE *parent)
  *	isn't possible.
  */
 static void
-__rec_subtree_row_clear(SESSION *session, WT_PAGE *parent)
+__rec_subtree_row_clear(WT_SESSION_IMPL *session, WT_PAGE *parent)
 {
 	WT_PAGE *page;
 	WT_ROW_REF *rref;
@@ -918,7 +918,7 @@ __rec_subtree_row_clear(SESSION *session, WT_PAGE *parent)
  * for discard.
  */
 static int
-__rec_ovfl_delete(SESSION *session, WT_PAGE *page)
+__rec_ovfl_delete(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
 	WT_CELL *cell;
 	WT_PAGE_DISK *dsk;
@@ -941,10 +941,10 @@ __rec_ovfl_delete(SESSION *session, WT_PAGE *page)
  *	Initialization for the reconciliation split functions.
  */
 static int
-__rec_split_init(
-    SESSION *session, WT_PAGE *page, uint64_t recno, uint32_t max, uint32_t min)
+__rec_split_init(WT_SESSION_IMPL *session,
+    WT_PAGE *page, uint64_t recno, uint32_t max, uint32_t min)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_PAGE_DISK *dsk;
 	WT_RECONCILE *r;
 
@@ -1030,7 +1030,7 @@ __rec_split_init(
  * has 3 doubled letters in a row?  Sweet-tooth does, too.)
  */
 static int
-__rec_split(SESSION *session)
+__rec_split(WT_SESSION_IMPL *session)
 {
 	WT_BOUNDARY *bnd;
 	WT_PAGE_DISK *dsk;
@@ -1172,7 +1172,7 @@ __rec_split(SESSION *session)
  *	Wrap up reconciliation.
  */
 static int
-__rec_split_finish(SESSION *session)
+__rec_split_finish(WT_SESSION_IMPL *session)
 {
 	WT_PAGE_DISK *dsk;
 	WT_RECONCILE *r;
@@ -1196,7 +1196,7 @@ __rec_split_finish(SESSION *session)
  *	Physically split the already-written page data.
  */
 static int
-__rec_split_fixup(SESSION *session)
+__rec_split_fixup(WT_SESSION_IMPL *session)
 {
 	WT_BOUNDARY *bnd;
 	WT_BUF *tmp;
@@ -1273,7 +1273,7 @@ err:	if (tmp != NULL)
  *	Write a disk block out for the split helper functions.
  */
 static int
-__rec_split_write(SESSION *session, WT_BUF *buf, void *end)
+__rec_split_write(WT_SESSION_IMPL *session, WT_BUF *buf, void *end)
 {
 	WT_CELL *cell;
 	WT_PAGE *page;
@@ -1359,7 +1359,7 @@ __rec_split_write(SESSION *session, WT_BUF *buf, void *end)
  *	Reconcile a column-store internal page.
  */
 static int
-__rec_col_int(SESSION *session, WT_PAGE *page)
+__rec_col_int(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
 	WT_RET(__rec_split_init(session, page,
 	    page->u.col_int.recno,
@@ -1386,7 +1386,7 @@ __rec_col_int(SESSION *session, WT_PAGE *page)
  *	Recursively walk a column-store internal tree of merge pages.
  */
 static int
-__rec_col_merge(SESSION *session, WT_PAGE *page)
+__rec_col_merge(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
 	WT_COL_REF *cref;
 	WT_OFF_RECORD off;
@@ -1450,9 +1450,9 @@ __rec_col_merge(SESSION *session, WT_PAGE *page)
  * run-length encoding).
  */
 static int
-__rec_col_fix(SESSION *session, WT_PAGE *page)
+__rec_col_fix(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_BUF *tmp;
 	WT_COL *cip;
 	WT_RECONCILE *r;
@@ -1530,9 +1530,9 @@ err:	if (tmp != NULL)
  * handle run-length encoding).
  */
 static int
-__rec_col_fix_bulk(SESSION *session, WT_PAGE *page)
+__rec_col_fix_bulk(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_RECONCILE *r;
 	WT_UPDATE *upd;
 	uint32_t len;
@@ -1567,9 +1567,9 @@ __rec_col_fix_bulk(SESSION *session, WT_PAGE *page)
  *	Reconcile a fixed-width, run-length encoded, column-store leaf page.
  */
 static int
-__rec_col_rle(SESSION *session, WT_PAGE *page)
+__rec_col_rle(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_BUF *tmp;
 	WT_COL *cip;
 	WT_INSERT *ins;
@@ -1588,7 +1588,7 @@ __rec_col_rle(SESSION *session, WT_PAGE *page)
 
 	/*
 	 * We need a "deleted" data item to store on the page.  Make sure the
-	 * SESSION's scratch buffer is big enough.  Clear the buffer's contents
+	 * session's scratch buffer is big enough.  Clear the buffer's contents
 	 * and set the delete flag.
 	 */
 	len = btree->fixed_len;
@@ -1680,9 +1680,9 @@ err:	if (tmp != NULL)
  *	leaf page.
  */
 static int
-__rec_col_rle_bulk(SESSION *session, WT_PAGE *page)
+__rec_col_rle_bulk(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_RECONCILE *r;
 	WT_UPDATE *upd;
 	uint32_t len;
@@ -1732,7 +1732,7 @@ __rec_col_rle_bulk(SESSION *session, WT_PAGE *page)
  *	Reconcile a variable-width column-store leaf page.
  */
 static int
-__rec_col_var(SESSION *session, WT_PAGE *page)
+__rec_col_var(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
 	WT_CELL *cell;
 	WT_COL *cip;
@@ -1801,7 +1801,7 @@ __rec_col_var(SESSION *session, WT_PAGE *page)
  *	Reconcile a bulk-loaded, variable-width column-store leaf page.
  */
 static int
-__rec_col_var_bulk(SESSION *session, WT_PAGE *page)
+__rec_col_var_bulk(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
 	WT_KV *val;
 	WT_RECONCILE *r;
@@ -1839,7 +1839,7 @@ __rec_col_var_bulk(SESSION *session, WT_PAGE *page)
  *	Reconcile a row-store internal page.
  */
 static int
-__rec_row_int(SESSION *session, WT_PAGE *page)
+__rec_row_int(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
 	WT_CELL *cell;
 	WT_KV *key, *val;
@@ -2047,7 +2047,7 @@ __rec_row_int(SESSION *session, WT_PAGE *page)
  *	Recursively walk a row-store internal tree of merge pages.
  */
 static int
-__rec_row_merge(SESSION *session, WT_PAGE *page)
+__rec_row_merge(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
 	WT_KV *key, *val;
 	WT_PAGE *rp;
@@ -2149,7 +2149,7 @@ __rec_row_merge(SESSION *session, WT_PAGE *page)
  *	Reconcile a row-store leaf page.
  */
 static int
-__rec_row_leaf(SESSION *session, WT_PAGE *page, uint32_t slvg_skip)
+__rec_row_leaf(WT_SESSION_IMPL *session, WT_PAGE *page, uint32_t slvg_skip)
 {
 	WT_CELL *cell, *val_cell;
 	WT_INSERT *ins;
@@ -2320,7 +2320,7 @@ leaf_insert:	/* Write any K/V pairs inserted into the page after this key. */
  *	Walk an insert chain, writing K/V pairs.
  */
 static int
-__rec_row_leaf_insert(SESSION *session, WT_INSERT *ins)
+__rec_row_leaf_insert(WT_SESSION_IMPL *session, WT_INSERT *ins)
 {
 	WT_KV *key, *val;
 	WT_RECONCILE *r;
@@ -2384,9 +2384,9 @@ __rec_row_leaf_insert(SESSION *session, WT_INSERT *ins)
  *	Resolve the WT_RECONCILE information.
  */
 static int
-__rec_wrapup(SESSION *session, WT_PAGE *page)
+__rec_wrapup(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_PAGE *imp;
 	WT_RECONCILE *r;
 
@@ -2552,7 +2552,7 @@ __rec_wrapup(SESSION *session, WT_PAGE *page)
  *	Update a parent page's reference for an evicted, clean page.
  */
 static void
-__rec_parent_update_clean(SESSION *session, WT_PAGE *page)
+__rec_parent_update_clean(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
 	WT_REF *parent_ref;
 
@@ -2579,7 +2579,7 @@ __rec_parent_update_clean(SESSION *session, WT_PAGE *page)
  *	Update a parent page's reference to a reconciled page.
  */
 static int
-__rec_parent_update(SESSION *session, WT_PAGE *page,
+__rec_parent_update(WT_SESSION_IMPL *session, WT_PAGE *page,
     WT_PAGE *replace, uint32_t addr, uint32_t size, uint32_t state)
 {
 	WT_REF *parent_ref;
@@ -2630,9 +2630,9 @@ __rec_parent_update(SESSION *session, WT_PAGE *page,
  * stored on the page.
  */
 static int
-__rec_cell_build_key(SESSION *session, const void *data, uint32_t size)
+__rec_cell_build_key(WT_SESSION_IMPL *session, const void *data, uint32_t size)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_KV *key;
 	WT_RECONCILE *r;
 	uint32_t pfx_len, pfx;
@@ -2713,9 +2713,9 @@ __rec_cell_build_key(SESSION *session, const void *data, uint32_t size)
  * be stored on the page.
  */
 static int
-__rec_cell_build_val(SESSION *session, void *data, uint32_t size)
+__rec_cell_build_val(WT_SESSION_IMPL *session, void *data, uint32_t size)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_KV *val;
 	WT_RECONCILE *r;
 
@@ -2760,7 +2760,7 @@ __rec_cell_build_val(SESSION *session, void *data, uint32_t size)
  *	Store bulk-loaded overflow items in the file, returning the WT_OFF.
  */
 static int
-__rec_cell_build_ovfl(SESSION *session, WT_KV *kv, u_int type)
+__rec_cell_build_ovfl(WT_SESSION_IMPL *session, WT_KV *kv, u_int type)
 {
 	WT_BUF *tmp;
 	WT_PAGE_DISK *dsk;
@@ -2827,7 +2827,7 @@ __rec_prefix_key_update(WT_RECONCILE *r)
  *	Update a row-store parent page's reference when a page is split.
  */
 static int
-__rec_row_split(SESSION *session, WT_PAGE **splitp, WT_PAGE *orig)
+__rec_row_split(WT_SESSION_IMPL *session, WT_PAGE **splitp, WT_PAGE *orig)
 {
 	WT_PAGE *imp, *page;
 	WT_RECONCILE *r;
@@ -2925,7 +2925,7 @@ err:	__wt_free(session, page);
  *	Update a column-store parent page's reference when a page is split.
  */
 static int
-__rec_col_split(SESSION *session, WT_PAGE **splitp, WT_PAGE *orig)
+__rec_col_split(WT_SESSION_IMPL *session, WT_PAGE **splitp, WT_PAGE *orig)
 {
 	WT_COL_REF *cref;
 	WT_OFF_RECORD *off;
@@ -3048,7 +3048,7 @@ __rec_imref_bsearch_cmp(const void *a, const void *b)
  *	Fix up after splitting a page referencing an in-memory subtree.
  */
 static int
-__rec_imref_fixup(SESSION *session, WT_PAGE *page)
+__rec_imref_fixup(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
 	WT_COL_REF *cref;
 	WT_RECONCILE *r;
@@ -3112,7 +3112,7 @@ __rec_imref_init(WT_RECONCILE *r)
  *	Append a new reference to the list of in-memory subtree references.
  */
 static int
-__rec_imref_add(SESSION *session, WT_REF *ref)
+__rec_imref_add(WT_SESSION_IMPL *session, WT_REF *ref)
 {
 	WT_RECONCILE *r;
 
@@ -3143,7 +3143,8 @@ __rec_discard_init(WT_RECONCILE *r)
  *	Append an object to the list of discard objects.
  */
 static int
-__rec_discard_add(SESSION *session, WT_PAGE *page, uint32_t addr, uint32_t size)
+__rec_discard_add(
+    WT_SESSION_IMPL *session, WT_PAGE *page, uint32_t addr, uint32_t size)
 {
 	WT_RECONCILE *r;
 
@@ -3167,7 +3168,7 @@ __rec_discard_add(SESSION *session, WT_PAGE *page, uint32_t addr, uint32_t size)
  *	Discard the list of discard objects.
  */
 static int
-__rec_discard_evict(SESSION *session)
+__rec_discard_evict(WT_SESSION_IMPL *session)
 {
 	WT_DISCARD *discard;
 	WT_RECONCILE *r;
@@ -3205,9 +3206,9 @@ __hazard_qsort_cmp(const void *a, const void *b)
  *	Copy the hazard array and prepare it for searching.
  */
 static void
-__hazard_copy(SESSION *session)
+__hazard_copy(WT_SESSION_IMPL *session)
 {
-	CONNECTION *conn;
+	WT_CONNECTION_IMPL *conn;
 	WT_RECONCILE *r;
 	uint32_t elem, i, j;
 
@@ -3249,7 +3250,7 @@ __hazard_bsearch_cmp(const void *search, const void *b)
  *	Request exclusive access to a page.
  */
 static int
-__hazard_exclusive(SESSION *session, WT_REF *ref)
+__hazard_exclusive(WT_SESSION_IMPL *session, WT_REF *ref)
 {
 	WT_RECONCILE *r;
 
diff --git a/src/btree/bt_ret.c b/src/btree/bt_ret.c
index 6e2b70f0d2d..de78c5d5a58 100644
--- a/src/btree/bt_ret.c
+++ b/src/btree/bt_ret.c
@@ -14,9 +14,10 @@
  *	Return a WT_PAGE/WT_{ROW,COL}_INDX pair to the application.
  */
 int
-__wt_return_data(SESSION *session, WT_ITEM *key, WT_ITEM *value, int key_return)
+__wt_return_data(
+    WT_SESSION_IMPL *session, WT_ITEM *key, WT_ITEM *value, int key_return)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_CURSOR *cursor;
 	WT_ITEM local_key, local_value;
 	WT_COL *cip;
@@ -26,7 +27,7 @@ __wt_return_data(SESSION *session, WT_ITEM *key, WT_ITEM *value, int key_return)
 	WT_UPDATE *upd;
 	const void *value_ret;
 	uint32_t size_ret;
-	int (*callback)(BTREE *, WT_ITEM *, WT_ITEM *), ret;
+	int (*callback)(WT_BTREE *, WT_ITEM *, WT_ITEM *), ret;
 
 	btree = session->btree;
 	cursor = session->cursor;
@@ -56,8 +57,8 @@ __wt_return_data(SESSION *session, WT_ITEM *key, WT_ITEM *value, int key_return)
 	 * allocate WT_ROW/COL memory for keys, but if we are looking at a key
 	 * only to return it, it's not that likely to be accessed again (think
 	 * of a cursor moving through the tree).  Use memory in the
-	 * application's WT_ITEM instead, it is discarded when the SESSION is
-	 * discarded.
+	 * application's WT_ITEM instead, it is discarded when the session is
+	 * closed.
 	 *
 	 * Key return implies a reference to a WT_ROW index (we don't return
 	 * record number keys yet, that will probably change when I add cursor
diff --git a/src/btree/bt_rw.c b/src/btree/bt_rw.c
index c26dfd5a6ac..efcbd09a4e8 100644
--- a/src/btree/bt_rw.c
+++ b/src/btree/bt_rw.c
@@ -13,9 +13,9 @@
  */
 int
 __wt_disk_read(
-    SESSION *session, WT_PAGE_DISK *dsk, uint32_t addr, uint32_t size)
+    WT_SESSION_IMPL *session, WT_PAGE_DISK *dsk, uint32_t addr, uint32_t size)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_FH *fh;
 	off_t offset;
 	uint32_t checksum;
@@ -47,9 +47,9 @@ __wt_disk_read(
  */
 int
 __wt_disk_write(
-    SESSION *session, WT_PAGE_DISK *dsk, uint32_t addr, uint32_t size)
+    WT_SESSION_IMPL *session, WT_PAGE_DISK *dsk, uint32_t addr, uint32_t size)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_FH *fh;
 
 	btree = session->btree;
diff --git a/src/btree/bt_salvage.c b/src/btree/bt_salvage.c
index 922024a7e81..036c5a89513 100644
--- a/src/btree/bt_salvage.c
+++ b/src/btree/bt_salvage.c
@@ -17,7 +17,7 @@ struct __wt_track; 		typedef struct __wt_track WT_TRACK;
  * to make the code prettier.
  */
 struct __wt_stuff {
-	BTREE	  *btree;			/* Enclosing Btree */
+	WT_BTREE	  *btree;			/* Enclosing Btree */
 
 	WT_TRACK **pages;			/* Pages */
 	uint32_t   pages_next;			/* Next empty slot */
@@ -74,32 +74,38 @@ struct __wt_track {
 	uint32_t flags;
 };
 
-static int  __slvg_build_internal_col(SESSION *, uint32_t, WT_STUFF *);
-static int  __slvg_build_internal_row(SESSION *, uint32_t, WT_STUFF *);
-static int  __slvg_build_leaf_col(SESSION *,
+static int  __slvg_build_internal_col(WT_SESSION_IMPL *, uint32_t, WT_STUFF *);
+static int  __slvg_build_internal_row(WT_SESSION_IMPL *, uint32_t, WT_STUFF *);
+static int  __slvg_build_leaf_col(WT_SESSION_IMPL *,
 		WT_TRACK *, WT_PAGE *, WT_COL_REF *, WT_STUFF *);
-static int  __slvg_build_leaf_row(SESSION *,
+static int  __slvg_build_leaf_row(WT_SESSION_IMPL *,
 		WT_TRACK *, WT_PAGE *, WT_ROW_REF *, WT_STUFF *, int *);
-static int  __slvg_discard_ovfl(SESSION *, WT_STUFF *);
-static int  __slvg_free(SESSION *, WT_STUFF *);
-static int  __slvg_free_merge_block(SESSION *, WT_STUFF *);
-static int  __slvg_free_trk_col(SESSION *, WT_TRACK **, int);
-static int  __slvg_free_trk_ovfl(SESSION *, WT_TRACK **, int);
-static int  __slvg_free_trk_row(SESSION *, WT_TRACK **, int);
-static int  __slvg_key_copy(SESSION *, WT_BUF *, WT_BUF *);
-static int  __slvg_ovfl_col_dsk_ref(SESSION *, WT_PAGE_DISK *, WT_TRACK *);
+static int  __slvg_discard_ovfl(WT_SESSION_IMPL *, WT_STUFF *);
+static int  __slvg_free(WT_SESSION_IMPL *, WT_STUFF *);
+static int  __slvg_free_merge_block(WT_SESSION_IMPL *, WT_STUFF *);
+static int  __slvg_free_trk_col(WT_SESSION_IMPL *, WT_TRACK **, int);
+static int  __slvg_free_trk_ovfl(WT_SESSION_IMPL *, WT_TRACK **, int);
+static int  __slvg_free_trk_row(WT_SESSION_IMPL *, WT_TRACK **, int);
+static int  __slvg_key_copy(WT_SESSION_IMPL *, WT_BUF *, WT_BUF *);
+static int  __slvg_ovfl_col_dsk_ref(
+        WT_SESSION_IMPL *, WT_PAGE_DISK *, WT_TRACK *);
 static void __slvg_ovfl_col_inmem_ref(WT_PAGE *, WT_STUFF *);
 static int  __slvg_ovfl_compare(const void *, const void *);
-static int  __slvg_ovfl_row_dsk_ref(SESSION *, WT_PAGE_DISK *, WT_TRACK *);
+static int  __slvg_ovfl_row_dsk_ref(
+        WT_SESSION_IMPL *, WT_PAGE_DISK *, WT_TRACK *);
 static void __slvg_ovfl_row_inmem_ref(WT_PAGE *, uint32_t, WT_STUFF *);
-static int  __slvg_range_col(SESSION *, WT_STUFF *);
-static int  __slvg_range_overlap_col(SESSION *, uint32_t, uint32_t, WT_STUFF *);
-static int  __slvg_range_overlap_row(SESSION *, uint32_t, uint32_t, WT_STUFF *);
-static int  __slvg_range_row(SESSION *, WT_STUFF *);
-static int  __slvg_read(SESSION *, WT_STUFF *);
+static int  __slvg_range_col(WT_SESSION_IMPL *, WT_STUFF *);
+static int  __slvg_range_overlap_col(
+        WT_SESSION_IMPL *, uint32_t, uint32_t, WT_STUFF *);
+static int  __slvg_range_overlap_row(
+        WT_SESSION_IMPL *, uint32_t, uint32_t, WT_STUFF *);
+static int  __slvg_range_row(WT_SESSION_IMPL *, WT_STUFF *);
+static int  __slvg_read(WT_SESSION_IMPL *, WT_STUFF *);
 static int  __slvg_trk_compare(const void *, const void *);
-static int  __slvg_trk_leaf(SESSION *, WT_PAGE_DISK *, uint32_t, WT_STUFF *);
-static int  __slvg_trk_ovfl(SESSION *, WT_PAGE_DISK *, uint32_t, WT_STUFF *);
+static int  __slvg_trk_leaf(
+        WT_SESSION_IMPL *, WT_PAGE_DISK *, uint32_t, WT_STUFF *);
+static int  __slvg_trk_ovfl(
+        WT_SESSION_IMPL *, WT_PAGE_DISK *, uint32_t, WT_STUFF *);
 static void __slvg_trk_ovfl_ref(WT_TRACK *, WT_STUFF *);
 
 #ifdef HAVE_DIAGNOSTIC
@@ -112,9 +118,9 @@ static void __slvg_trk_dump_row(WT_TRACK *);
  *	Salvage a Btree.
  */
 int
-__wt_salvage(SESSION *session, const char *config)
+__wt_salvage(WT_SESSION_IMPL *session, const char *config)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_STUFF *ss, stuff;
 	off_t len;
 	uint32_t allocsize, i, leaf_cnt;
@@ -265,9 +271,9 @@ err:	/* Wrap up reporting. */
  *	Read the file and build a table of the pages we can use.
  */
 static int
-__slvg_read(SESSION *session, WT_STUFF *ss)
+__slvg_read(WT_SESSION_IMPL *session, WT_STUFF *ss)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_BUF *t;
 	WT_FH *fh;
 	WT_PAGE_DISK *dsk;
@@ -416,9 +422,9 @@ err:	__wt_scr_release(&t);
  */
 static int
 __slvg_trk_leaf(
-    SESSION *session, WT_PAGE_DISK *dsk, uint32_t addr, WT_STUFF *ss)
+    WT_SESSION_IMPL *session, WT_PAGE_DISK *dsk, uint32_t addr, WT_STUFF *ss)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_CELL *cell, *last_key_cell;
 	WT_TRACK *trk;
 	uint64_t stop_recno;
@@ -513,7 +519,7 @@ err:		if (trk != NULL)
  */
 static int
 __slvg_trk_ovfl(
-    SESSION *session, WT_PAGE_DISK *dsk, uint32_t addr, WT_STUFF *ss)
+    WT_SESSION_IMPL *session, WT_PAGE_DISK *dsk, uint32_t addr, WT_STUFF *ss)
 {
 	WT_TRACK *trk;
 
@@ -538,7 +544,8 @@ __slvg_trk_ovfl(
  *	Search a column-store page for overflow items.
  */
 static int
-__slvg_ovfl_col_dsk_ref(SESSION *session, WT_PAGE_DISK *dsk, WT_TRACK *trk)
+__slvg_ovfl_col_dsk_ref(
+    WT_SESSION_IMPL *session, WT_PAGE_DISK *dsk, WT_TRACK *trk)
 {
 	WT_CELL *cell;
 	WT_OFF ovfl;
@@ -574,7 +581,8 @@ __slvg_ovfl_col_dsk_ref(SESSION *session, WT_PAGE_DISK *dsk, WT_TRACK *trk)
  *	Search a row-store page for overflow items.
  */
 static int
-__slvg_ovfl_row_dsk_ref(SESSION *session, WT_PAGE_DISK *dsk, WT_TRACK *trk)
+__slvg_ovfl_row_dsk_ref(
+    WT_SESSION_IMPL *session, WT_PAGE_DISK *dsk, WT_TRACK *trk)
 {
 	WT_CELL *cell;
 	WT_OFF ovfl;
@@ -697,7 +705,7 @@ __slvg_ovfl_row_dsk_ref(SESSION *session, WT_PAGE_DISK *dsk, WT_TRACK *trk)
  * re-sorting the array is small.
  */
 static int
-__slvg_range_col(SESSION *session, WT_STUFF *ss)
+__slvg_range_col(WT_SESSION_IMPL *session, WT_STUFF *ss)
 {
 	uint32_t i, j;
 
@@ -748,7 +756,7 @@ __slvg_range_col(SESSION *session, WT_STUFF *ss)
  */
 static int
 __slvg_range_overlap_col(
-    SESSION *session, uint32_t a_slot, uint32_t b_slot, WT_STUFF *ss)
+    WT_SESSION_IMPL *session, uint32_t a_slot, uint32_t b_slot, WT_STUFF *ss)
 {
 	WT_TRACK *a_trk, *b_trk, *new;
 	uint32_t i, j;
@@ -913,7 +921,8 @@ delete:		WT_RET(__slvg_free_trk_col(session, &ss->pages[b_slot], 1));
  *	pages we've found.
  */
 static int
-__slvg_build_internal_col(SESSION *session, uint32_t leaf_cnt, WT_STUFF *ss)
+__slvg_build_internal_col(
+    WT_SESSION_IMPL *session, uint32_t leaf_cnt, WT_STUFF *ss)
 {
 	WT_COL_REF *cref;
 	WT_PAGE *page;
@@ -998,7 +1007,7 @@ err:	if (page->u.col_int.t != NULL)
  *	Build a column-store leaf page for a merged page.
  */
 static int
-__slvg_build_leaf_col(SESSION *session,
+__slvg_build_leaf_col(WT_SESSION_IMPL *session,
     WT_TRACK *trk, WT_PAGE *parent, WT_COL_REF *cref, WT_STUFF *ss)
 {
 	WT_COL *cip, *save_col_leaf;
@@ -1152,11 +1161,11 @@ __slvg_ovfl_col_inmem_ref(WT_PAGE *page, WT_STUFF *ss)
  * same time, tag the overflow pages they reference.
  */
 static int
-__slvg_range_row(SESSION *session, WT_STUFF *ss)
+__slvg_range_row(WT_SESSION_IMPL *session, WT_STUFF *ss)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	uint32_t i, j;
-	int (*func)(BTREE *, const WT_ITEM *, const WT_ITEM *);
+	int (*func)(WT_BTREE *, const WT_ITEM *, const WT_ITEM *);
 
 	btree = session->btree;
 	func = btree->btree_compare;
@@ -1209,12 +1218,12 @@ __slvg_range_row(SESSION *session, WT_STUFF *ss)
  */
 static int
 __slvg_range_overlap_row(
-    SESSION *session, uint32_t a_slot, uint32_t b_slot, WT_STUFF *ss)
+    WT_SESSION_IMPL *session, uint32_t a_slot, uint32_t b_slot, WT_STUFF *ss)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_TRACK *a_trk, *b_trk, *new;
 	uint32_t i, j;
-	int (*func)(BTREE *, const WT_ITEM *, const WT_ITEM *);
+	int (*func)(WT_BTREE *, const WT_ITEM *, const WT_ITEM *);
 
 	/*
 	 * DO NOT MODIFY THIS CODE WITHOUT REVIEWING THE CORRESPONDING ROW- OR
@@ -1391,7 +1400,8 @@ delete:		WT_RET(__slvg_free_trk_row(session, &ss->pages[b_slot], 1));
  *	pages we've found.
  */
 static int
-__slvg_build_internal_row(SESSION *session, uint32_t leaf_cnt, WT_STUFF *ss)
+__slvg_build_internal_row(
+    WT_SESSION_IMPL *session, uint32_t leaf_cnt, WT_STUFF *ss)
 {
 	WT_PAGE *page;
 	WT_ROW_REF *rref;
@@ -1479,15 +1489,15 @@ err:	if (page->u.row_int.t != NULL)
  *	Build a row-store leaf page for a merged page.
  */
 static int
-__slvg_build_leaf_row(SESSION *session, WT_TRACK *trk,
+__slvg_build_leaf_row(WT_SESSION_IMPL *session, WT_TRACK *trk,
     WT_PAGE *parent, WT_ROW_REF *rref, WT_STUFF *ss, int *deletedp)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_BUF *key;
 	WT_PAGE *page;
 	WT_ROW *rip;
 	uint32_t i, skip_start, skip_stop;
-	int (*func)(BTREE *, const WT_ITEM *, const WT_ITEM *), ret;
+	int (*func)(WT_BTREE *, const WT_ITEM *, const WT_ITEM *), ret;
 	void *item;
 
 	btree = session->btree;
@@ -1731,7 +1741,7 @@ __slvg_ovfl_compare(const void *a, const void *b)
 static int
 __slvg_trk_compare(const void *a, const void *b)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_TRACK *a_trk, *b_trk;
 	uint64_t a_lsn, a_recno, b_lsn, b_recno;
 	int cmp;
@@ -1776,7 +1786,7 @@ __slvg_trk_compare(const void *a, const void *b)
  *	Copy a WT_TRACK start/stop key to another WT_TRACK start/stop key.
  */
 static int
-__slvg_key_copy(SESSION *session, WT_BUF *dst, WT_BUF *src)
+__slvg_key_copy(WT_SESSION_IMPL *session, WT_BUF *dst, WT_BUF *src)
 {
 	return (__wt_buf_set(session, dst, src->data, src->size));
 }
@@ -1786,7 +1796,7 @@ __slvg_key_copy(SESSION *session, WT_BUF *dst, WT_BUF *src)
  *	Discard any overflow pages that are never referenced.
  */
 static int
-__slvg_discard_ovfl(SESSION *session, WT_STUFF *ss)
+__slvg_discard_ovfl(WT_SESSION_IMPL *session, WT_STUFF *ss)
 {
 	WT_TRACK *trk, **p, **t;
 	uint32_t i;
@@ -1815,7 +1825,7 @@ __slvg_discard_ovfl(SESSION *session, WT_STUFF *ss)
  *	Free any file blocks that had to be merged back into the free-list.
  */
 static int
-__slvg_free_merge_block(SESSION *session, WT_STUFF *ss)
+__slvg_free_merge_block(WT_SESSION_IMPL *session, WT_STUFF *ss)
 {
 	WT_TRACK *trk;
 	uint32_t i;
@@ -1852,7 +1862,7 @@ __slvg_free_merge_block(SESSION *session, WT_STUFF *ss)
  *	Discard memory allocated to the page and overflow arrays.
  */
 static int
-__slvg_free(SESSION *session, WT_STUFF *ss)
+__slvg_free(WT_SESSION_IMPL *session, WT_STUFF *ss)
 {
 	uint32_t i;
 
@@ -1887,7 +1897,7 @@ __slvg_free(SESSION *session, WT_STUFF *ss)
  *	Discard a column-store WT_TRACK structure and all its resources.
  */
 static int
-__slvg_free_trk_col(SESSION *session, WT_TRACK **trkp, int blocks)
+__slvg_free_trk_col(WT_SESSION_IMPL *session, WT_TRACK **trkp, int blocks)
 {
 	WT_TRACK *trk;
 
@@ -1908,7 +1918,7 @@ __slvg_free_trk_col(SESSION *session, WT_TRACK **trkp, int blocks)
  *	Discard a row-store WT_TRACK structure and all its resources.
  */
 static int
-__slvg_free_trk_row(SESSION *session, WT_TRACK **trkp, int blocks)
+__slvg_free_trk_row(WT_SESSION_IMPL *session, WT_TRACK **trkp, int blocks)
 {
 	WT_TRACK *trk;
 
@@ -1932,7 +1942,7 @@ __slvg_free_trk_row(SESSION *session, WT_TRACK **trkp, int blocks)
  *	Discard a overflow WT_TRACK structure and all its resources.
  */
 static int
-__slvg_free_trk_ovfl(SESSION *session, WT_TRACK **trkp, int blocks)
+__slvg_free_trk_ovfl(WT_SESSION_IMPL *session, WT_TRACK **trkp, int blocks)
 {
 	WT_TRACK *trk;
 
diff --git a/src/btree/bt_stat.c b/src/btree/bt_stat.c
index 3c0247037b4..35b82cc8aa5 100644
--- a/src/btree/bt_stat.c
+++ b/src/btree/bt_stat.c
@@ -8,17 +8,17 @@
 #include "wt_internal.h"
 #include "cell.i"
 
-static int __wt_stat_page_col_fix(SESSION *, WT_PAGE *);
-static int __wt_stat_page_col_rle(SESSION *, WT_PAGE *);
-static int __wt_stat_page_col_var(SESSION *, WT_PAGE *);
-static int __wt_stat_page_row_leaf(SESSION *, WT_PAGE *, void *);
+static int __wt_stat_page_col_fix(WT_SESSION_IMPL *, WT_PAGE *);
+static int __wt_stat_page_col_rle(WT_SESSION_IMPL *, WT_PAGE *);
+static int __wt_stat_page_col_var(WT_SESSION_IMPL *, WT_PAGE *);
+static int __wt_stat_page_row_leaf(WT_SESSION_IMPL *, WT_PAGE *, void *);
 
 /*
  * __wt_page_stat --
  *	Stat any Btree page.
  */
 int
-__wt_page_stat(SESSION *session, WT_PAGE *page, void *arg)
+__wt_page_stat(WT_SESSION_IMPL *session, WT_PAGE *page, void *arg)
 {
 	WT_BTREE_FILE_STATS *stats;
 
@@ -64,7 +64,7 @@ __wt_page_stat(SESSION *session, WT_PAGE *page, void *arg)
  *	Stat a WT_PAGE_COL_FIX page.
  */
 static int
-__wt_stat_page_col_fix(SESSION *session, WT_PAGE *page)
+__wt_stat_page_col_fix(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
 	WT_BTREE_FILE_STATS *stats;
 	WT_COL *cip;
@@ -93,7 +93,7 @@ __wt_stat_page_col_fix(SESSION *session, WT_PAGE *page)
  *	Stat a WT_PAGE_COL_RLE page.
  */
 static int
-__wt_stat_page_col_rle(SESSION *session, WT_PAGE *page)
+__wt_stat_page_col_rle(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
 	WT_BTREE_FILE_STATS *stats;
 	WT_COL *cip;
@@ -147,7 +147,7 @@ __wt_stat_page_col_rle(SESSION *session, WT_PAGE *page)
  *	Stat a WT_PAGE_COL_VAR page.
  */
 static int
-__wt_stat_page_col_var(SESSION *session, WT_PAGE *page)
+__wt_stat_page_col_var(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
 	WT_BTREE_FILE_STATS *stats;
 	WT_COL *cip;
@@ -186,7 +186,7 @@ __wt_stat_page_col_var(SESSION *session, WT_PAGE *page)
  *	Stat a WT_PAGE_ROW_LEAF page.
  */
 static int
-__wt_stat_page_row_leaf(SESSION *session, WT_PAGE *page, void *arg)
+__wt_stat_page_row_leaf(WT_SESSION_IMPL *session, WT_PAGE *page, void *arg)
 {
 	WT_BTREE_FILE_STATS *stats;
 	WT_INSERT *ins;
diff --git a/src/btree/bt_sync.c b/src/btree/bt_sync.c
index 0d59dd14865..e7e04be3cb5 100644
--- a/src/btree/bt_sync.c
+++ b/src/btree/bt_sync.c
@@ -12,7 +12,7 @@
  *	Sync the tree.
  */
 int
-__wt_bt_sync(SESSION *session)
+__wt_bt_sync(WT_SESSION_IMPL *session)
 {
 	int ret;
 
diff --git a/src/btree/bt_vrfy.c b/src/btree/bt_vrfy.c
index 55d50e35076..40026f47ec8 100644
--- a/src/btree/bt_vrfy.c
+++ b/src/btree/bt_vrfy.c
@@ -26,24 +26,26 @@ typedef struct {
 	uint32_t max_addr;			/* Largest key page */
 } WT_VSTUFF;
 
-static int __wt_verify_addfrag(SESSION *, uint32_t, uint32_t, WT_VSTUFF *);
-static int __wt_verify_checkfrag(SESSION *, WT_VSTUFF *);
-static int __wt_verify_freelist(SESSION *, WT_VSTUFF *);
-static int __wt_verify_overflow(SESSION *, WT_OFF *, WT_VSTUFF *);
-static int __wt_verify_overflow_page(SESSION *, WT_PAGE *, WT_VSTUFF *);
+static int __wt_verify_addfrag(
+        WT_SESSION_IMPL *, uint32_t, uint32_t, WT_VSTUFF *);
+static int __wt_verify_checkfrag(WT_SESSION_IMPL *, WT_VSTUFF *);
+static int __wt_verify_freelist(WT_SESSION_IMPL *, WT_VSTUFF *);
+static int __wt_verify_overflow(WT_SESSION_IMPL *, WT_OFF *, WT_VSTUFF *);
+static int __wt_verify_overflow_page(WT_SESSION_IMPL *, WT_PAGE *, WT_VSTUFF *);
 static int __wt_verify_row_int_key_order(
-		SESSION *, WT_PAGE *, void *, WT_VSTUFF *);
-static int __wt_verify_row_leaf_key_order(SESSION *, WT_PAGE *, WT_VSTUFF *);
-static int __wt_verify_tree(SESSION *, WT_REF *, uint64_t, WT_VSTUFF *);
+        WT_SESSION_IMPL *, WT_PAGE *, void *, WT_VSTUFF *);
+static int __wt_verify_row_leaf_key_order(
+        WT_SESSION_IMPL *, WT_PAGE *, WT_VSTUFF *);
+static int __wt_verify_tree(WT_SESSION_IMPL *, WT_REF *, uint64_t, WT_VSTUFF *);
 
 /*
  * __wt_verify --
  *	Verify a Btree, optionally dumping each page in debugging mode.
  */
 int
-__wt_verify(SESSION *session, FILE *stream, const char *config)
+__wt_verify(WT_SESSION_IMPL *session, FILE *stream, const char *config)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_VSTUFF *vs, _vstuff;
 	int ret;
 
@@ -128,7 +130,7 @@ err:	if (vs != NULL) {
  */
 static int
 __wt_verify_tree(
-	SESSION *session,		/* Thread of control */
+	WT_SESSION_IMPL *session,		/* Thread of control */
 	WT_REF *ref,			/* Page to verify */
 	uint64_t parent_recno,		/* First record in this subtree */
 	WT_VSTUFF *vs)			/* The verify package */
@@ -331,11 +333,11 @@ recno_chk:	if (parent_recno != recno) {
  */
 static int
 __wt_verify_row_int_key_order(
-    SESSION *session, WT_PAGE *page, void *rref, WT_VSTUFF *vs)
+    WT_SESSION_IMPL *session, WT_PAGE *page, void *rref, WT_VSTUFF *vs)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_BUF *key, *tmp;
-	int ret, (*func)(BTREE *, const WT_ITEM *, const WT_ITEM *);
+	int ret, (*func)(WT_BTREE *, const WT_ITEM *, const WT_ITEM *);
 
 	btree = session->btree;
 	key = NULL;
@@ -375,11 +377,12 @@ __wt_verify_row_int_key_order(
  * far; update the largest key we've seen so far to the last key on the page.
  */
 static int
-__wt_verify_row_leaf_key_order(SESSION *session, WT_PAGE *page, WT_VSTUFF *vs)
+__wt_verify_row_leaf_key_order(
+    WT_SESSION_IMPL *session, WT_PAGE *page, WT_VSTUFF *vs)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_BUF *key;
-	int ret, (*func)(BTREE *, const WT_ITEM *, const WT_ITEM *);
+	int ret, (*func)(WT_BTREE *, const WT_ITEM *, const WT_ITEM *);
 
 	btree = session->btree;
 	key = NULL;
@@ -429,7 +432,8 @@ __wt_verify_row_leaf_key_order(SESSION *session, WT_PAGE *page, WT_VSTUFF *vs)
  *	Verify overflow items.
  */
 static int
-__wt_verify_overflow_page(SESSION *session, WT_PAGE *page, WT_VSTUFF *vs)
+__wt_verify_overflow_page(
+    WT_SESSION_IMPL *session, WT_PAGE *page, WT_VSTUFF *vs)
 {
 	WT_CELL *cell;
 	WT_OFF ovfl;
@@ -460,7 +464,7 @@ __wt_verify_overflow_page(SESSION *session, WT_PAGE *page, WT_VSTUFF *vs)
  *	Read in an overflow page and check it.
  */
 static int
-__wt_verify_overflow(SESSION *session, WT_OFF *ovfl, WT_VSTUFF *vs)
+__wt_verify_overflow(WT_SESSION_IMPL *session, WT_OFF *ovfl, WT_VSTUFF *vs)
 {
 	WT_PAGE_DISK *dsk;
 	WT_BUF *tmp;
@@ -502,9 +506,9 @@ err:	__wt_scr_release(&tmp);
  *	Add the freelist fragments to the list of verified fragments.
  */
 static int
-__wt_verify_freelist(SESSION *session, WT_VSTUFF *vs)
+__wt_verify_freelist(WT_SESSION_IMPL *session, WT_VSTUFF *vs)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_FREE_ENTRY *fe;
 	int ret;
 
@@ -524,9 +528,9 @@ __wt_verify_freelist(SESSION *session, WT_VSTUFF *vs)
  */
 static int
 __wt_verify_addfrag(
-    SESSION *session, uint32_t addr, uint32_t size, WT_VSTUFF *vs)
+    WT_SESSION_IMPL *session, uint32_t addr, uint32_t size, WT_VSTUFF *vs)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	uint32_t frags, i;
 
 	btree = session->btree;
@@ -549,7 +553,7 @@ __wt_verify_addfrag(
  *	Verify we've checked all the fragments in the file.
  */
 static int
-__wt_verify_checkfrag(SESSION *session, WT_VSTUFF *vs)
+__wt_verify_checkfrag(WT_SESSION_IMPL *session, WT_VSTUFF *vs)
 {
 	int ffc, ffc_start, ffc_end, frags, ret;
 
diff --git a/src/btree/bt_vrfy_dsk.c b/src/btree/bt_vrfy_dsk.c
index e907a9aa316..82f034cfffd 100644
--- a/src/btree/bt_vrfy_dsk.c
+++ b/src/btree/bt_vrfy_dsk.c
@@ -9,21 +9,22 @@
 #include "cell.i"
 
 static int __wt_err_cell_vs_page(
-	SESSION *, uint32_t, uint32_t, WT_CELL *, WT_PAGE_DISK *);
-static int __wt_err_delfmt(SESSION *, uint32_t, uint32_t);
-static int __wt_err_eof(SESSION *, uint32_t, uint32_t);
-static int __wt_err_eop(SESSION *, uint32_t, uint32_t);
+	WT_SESSION_IMPL *, uint32_t, uint32_t, WT_CELL *, WT_PAGE_DISK *);
+static int __wt_err_delfmt(WT_SESSION_IMPL *, uint32_t, uint32_t);
+static int __wt_err_eof(WT_SESSION_IMPL *, uint32_t, uint32_t);
+static int __wt_err_eop(WT_SESSION_IMPL *, uint32_t, uint32_t);
 static int __wt_verify_cell(
-	SESSION *, WT_CELL *, uint32_t, uint32_t, uint8_t *);
-static int __wt_verify_dsk_row(SESSION *, WT_PAGE_DISK *, uint32_t, uint32_t);
+	WT_SESSION_IMPL *, WT_CELL *, uint32_t, uint32_t, uint8_t *);
+static int __wt_verify_dsk_row(
+        WT_SESSION_IMPL *, WT_PAGE_DISK *, uint32_t, uint32_t);
 static int __wt_verify_dsk_col_fix(
-	SESSION *, WT_PAGE_DISK *, uint32_t, uint32_t);
+	WT_SESSION_IMPL *, WT_PAGE_DISK *, uint32_t, uint32_t);
 static int __wt_verify_dsk_col_int(
-	SESSION *, WT_PAGE_DISK *, uint32_t, uint32_t);
+	WT_SESSION_IMPL *, WT_PAGE_DISK *, uint32_t, uint32_t);
 static int __wt_verify_dsk_col_rle(
-	SESSION *, WT_PAGE_DISK *, uint32_t, uint32_t);
+	WT_SESSION_IMPL *, WT_PAGE_DISK *, uint32_t, uint32_t);
 static int __wt_verify_dsk_col_var(
-	SESSION *, WT_PAGE_DISK *, uint32_t, uint32_t);
+	WT_SESSION_IMPL *, WT_PAGE_DISK *, uint32_t, uint32_t);
 
 /*
  * __wt_verify_dsk_page --
@@ -31,7 +32,7 @@ static int __wt_verify_dsk_col_var(
  */
 int
 __wt_verify_dsk_page(
-    SESSION *session, WT_PAGE_DISK *dsk, uint32_t addr, uint32_t size)
+    WT_SESSION_IMPL *session, WT_PAGE_DISK *dsk, uint32_t addr, uint32_t size)
 {
 	/* Check the page type. */
 	switch (dsk->type) {
@@ -127,9 +128,9 @@ __wt_verify_dsk_page(
  */
 static int
 __wt_verify_dsk_row(
-    SESSION *session, WT_PAGE_DISK *dsk, uint32_t addr, uint32_t size)
+    WT_SESSION_IMPL *session, WT_PAGE_DISK *dsk, uint32_t addr, uint32_t size)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_BUF *current, *last, *last_pfx, *last_ovfl;
 	WT_CELL *cell;
 	WT_OFF off;
@@ -139,7 +140,7 @@ __wt_verify_dsk_row(
 	uint32_t cell_num, cell_type, data_size, i, prefix;
 	uint8_t *end;
 	int ret;
-	int (*func)(BTREE *, const WT_ITEM *, const WT_ITEM *);
+	int (*func)(WT_BTREE *, const WT_ITEM *, const WT_ITEM *);
 
 	btree = session->btree;
 	func = btree->btree_compare;
@@ -384,9 +385,9 @@ err:		if (ret == 0)
  */
 static int
 __wt_verify_dsk_col_int(
-    SESSION *session, WT_PAGE_DISK *dsk, uint32_t addr, uint32_t size)
+    WT_SESSION_IMPL *session, WT_PAGE_DISK *dsk, uint32_t addr, uint32_t size)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_OFF_RECORD *off_record;
 	uint8_t *end;
 	uint32_t i, entry_num;
@@ -417,9 +418,9 @@ __wt_verify_dsk_col_int(
  */
 static int
 __wt_verify_dsk_col_fix(
-    SESSION *session, WT_PAGE_DISK *dsk, uint32_t addr, uint32_t size)
+    WT_SESSION_IMPL *session, WT_PAGE_DISK *dsk, uint32_t addr, uint32_t size)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	u_int len;
 	uint32_t i, j, entry_num;
 	uint8_t *data, *end, *p;
@@ -458,9 +459,9 @@ delfmt:	return (__wt_err_delfmt(session, entry_num, addr));
  */
 static int
 __wt_verify_dsk_col_rle(
-    SESSION *session, WT_PAGE_DISK *dsk, uint32_t addr, uint32_t size)
+    WT_SESSION_IMPL *session, WT_PAGE_DISK *dsk, uint32_t addr, uint32_t size)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	u_int len;
 	uint32_t i, j, entry_num;
 	uint8_t *data, *end, *last_data, *p;
@@ -528,9 +529,9 @@ delfmt:	return (__wt_err_delfmt(session, entry_num, addr));
  */
 static int
 __wt_verify_dsk_col_var(
-    SESSION *session, WT_PAGE_DISK *dsk, uint32_t addr, uint32_t size)
+    WT_SESSION_IMPL *session, WT_PAGE_DISK *dsk, uint32_t addr, uint32_t size)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_CELL *cell;
 	WT_OFF off;
 	off_t file_size;
@@ -578,7 +579,7 @@ __wt_verify_dsk_col_var(
  */
 int
 __wt_verify_dsk_chunk(
-    SESSION *session, WT_PAGE_DISK *dsk, uint32_t addr, uint32_t size)
+    WT_SESSION_IMPL *session, WT_PAGE_DISK *dsk, uint32_t addr, uint32_t size)
 {
 	uint32_t len;
 	uint8_t *p;
@@ -614,7 +615,7 @@ __wt_verify_dsk_chunk(
  *	Check to see if a cell is safe.
  */
 static int
-__wt_verify_cell(SESSION *session,
+__wt_verify_cell(WT_SESSION_IMPL *session,
     WT_CELL *cell, uint32_t cell_num, uint32_t addr, uint8_t *end)
 {
 	uint8_t *p;
@@ -674,7 +675,7 @@ __wt_verify_cell(SESSION *session,
  *	Generic illegal cell type for a particular page type error.
  */
 static int
-__wt_err_cell_vs_page(SESSION *session,
+__wt_err_cell_vs_page(WT_SESSION_IMPL *session,
     uint32_t entry_num, uint32_t addr, WT_CELL *cell, WT_PAGE_DISK *dsk)
 {
 	__wt_errx(session,
@@ -691,7 +692,7 @@ __wt_err_cell_vs_page(SESSION *session,
  *	Generic item extends past the end-of-page error.
  */
 static int
-__wt_err_eop(SESSION *session, uint32_t entry_num, uint32_t addr)
+__wt_err_eop(WT_SESSION_IMPL *session, uint32_t entry_num, uint32_t addr)
 {
 	__wt_errx(session,
 	    "item %lu on page at addr %lu extends past the end of the page",
@@ -704,7 +705,7 @@ __wt_err_eop(SESSION *session, uint32_t entry_num, uint32_t addr)
  *	Generic item references non-existent file pages error.
  */
 static int
-__wt_err_eof(SESSION *session, uint32_t entry_num, uint32_t addr)
+__wt_err_eof(WT_SESSION_IMPL *session, uint32_t entry_num, uint32_t addr)
 {
 	__wt_errx(session,
 	    "off-page item %lu on page at addr %lu references non-existent "
@@ -719,7 +720,7 @@ __wt_err_eof(SESSION *session, uint32_t entry_num, uint32_t addr)
  *	non-nul bytes.
  */
 static int
-__wt_err_delfmt(SESSION *session, uint32_t entry_num, uint32_t addr)
+__wt_err_delfmt(WT_SESSION_IMPL *session, uint32_t entry_num, uint32_t addr)
 {
 	__wt_errx(session,
 	    "deleted fixed-length entry %lu on page at addr %lu has non-nul "
diff --git a/src/btree/bt_walk.c b/src/btree/bt_walk.c
index 86560c02830..04a169f9943 100644
--- a/src/btree/bt_walk.c
+++ b/src/btree/bt_walk.c
@@ -21,7 +21,7 @@
  *    + to walk the tree a few pages at a time, that is, periodically wake,
  *	visit some pages, then go back to sleep, which requires enough state
  *	to restart the traversal at any point,
- *    + to walk files not associated with the current SESSION's BTREE handle,
+ *    + to walk files not associated with the current session's WT_BTREE handle,
  *    + and finally, it doesn't require a hazard reference.
  *
  * My guess is we'll generalize a more complicated walk at some point, which
@@ -35,10 +35,10 @@
  *	each page.
  */
 int
-__wt_tree_walk(SESSION *session,
-    WT_PAGE *page, int (*work)(SESSION *, WT_PAGE *, void *), void *arg)
+__wt_tree_walk(WT_SESSION_IMPL *session,
+    WT_PAGE *page, int (*work)(WT_SESSION_IMPL *, WT_PAGE *, void *), void *arg)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_COL_REF *cref;
 	WT_ROW_REF *rref;
 	uint32_t i;
@@ -93,9 +93,10 @@ __wt_tree_walk(SESSION *session,
  *	Start a tree walk.
  */
 int
-__wt_walk_begin(SESSION *session, WT_PAGE *page, WT_WALK *walk, uint32_t flags)
+__wt_walk_begin(
+    WT_SESSION_IMPL *session, WT_PAGE *page, WT_WALK *walk, uint32_t flags)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 
 	btree = session->btree;
 
@@ -127,7 +128,7 @@ __wt_walk_begin(SESSION *session, WT_PAGE *page, WT_WALK *walk, uint32_t flags)
  *	End a tree walk.
  */
 void
-__wt_walk_end(SESSION *session, WT_WALK *walk)
+__wt_walk_end(WT_SESSION_IMPL *session, WT_WALK *walk)
 {
 	WT_WALK_ENTRY *e;
 
@@ -148,7 +149,7 @@ __wt_walk_end(SESSION *session, WT_WALK *walk)
  *	Return the next WT_PAGE in the tree, in a non-recursive way.
  */
 int
-__wt_walk_next(SESSION *session, WT_WALK *walk, WT_PAGE **pagep)
+__wt_walk_next(WT_SESSION_IMPL *session, WT_WALK *walk, WT_PAGE **pagep)
 {
 	WT_PAGE *page;
 	WT_REF *ref;
diff --git a/src/btree/col_get.c b/src/btree/col_get.c
index ef0e8400abc..96f12fdf308 100644
--- a/src/btree/col_get.c
+++ b/src/btree/col_get.c
@@ -12,9 +12,9 @@
  *	Db.col_get method.
  */
 int
-__wt_btree_col_get(SESSION *session, uint64_t recno, WT_ITEM *value)
+__wt_btree_col_get(WT_SESSION_IMPL *session, uint64_t recno, WT_ITEM *value)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	int ret;
 
 	btree = session->btree;
diff --git a/src/btree/col_put.c b/src/btree/col_put.c
index 73a4557d4a0..12b4fa81dfa 100644
--- a/src/btree/col_put.c
+++ b/src/btree/col_put.c
@@ -7,16 +7,16 @@
 
 #include "wt_internal.h"
 
-static int __col_wrong_fixed_size(SESSION *, uint32_t, uint32_t);
-static int __col_insert_alloc(SESSION *, uint64_t, WT_INSERT **);
-static int __col_update(SESSION *, uint64_t, WT_ITEM *, int);
+static int __col_wrong_fixed_size(WT_SESSION_IMPL *, uint32_t, uint32_t);
+static int __col_insert_alloc(WT_SESSION_IMPL *, uint64_t, WT_INSERT **);
+static int __col_update(WT_SESSION_IMPL *, uint64_t, WT_ITEM *, int);
 
 /*
  * __wt_btree_col_del --
  *	Db.col_del method.
  */
 int
-__wt_btree_col_del(SESSION *session, uint64_t recno)
+__wt_btree_col_del(WT_SESSION_IMPL *session, uint64_t recno)
 {
 	int ret;
 
@@ -30,9 +30,9 @@ __wt_btree_col_del(SESSION *session, uint64_t recno)
  *	Db.put method.
  */
 int
-__wt_btree_col_put(SESSION *session, uint64_t recno, WT_ITEM *value)
+__wt_btree_col_put(WT_SESSION_IMPL *session, uint64_t recno, WT_ITEM *value)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	int ret;
 
 	btree = session->btree;
@@ -51,7 +51,8 @@ __wt_btree_col_put(SESSION *session, uint64_t recno, WT_ITEM *value)
  *	Column-store delete and update.
  */
 static int
-__col_update(SESSION *session, uint64_t recno, WT_ITEM *value, int is_write)
+__col_update(
+    WT_SESSION_IMPL *session, uint64_t recno, WT_ITEM *value, int is_write)
 {
 	WT_PAGE *page;
 	WT_INSERT **new_ins, *ins;
@@ -160,13 +161,13 @@ err:		if (ins != NULL)
 
 /*
  * __col_insert_alloc --
- *	Column-store insert: allocate a WT_INSERT structure from the SESSION's
+ *	Column-store insert: allocate a WT_INSERT structure from the session's
  *	buffer and fill it in.
  */
 static int
-__col_insert_alloc(SESSION *session, uint64_t recno, WT_INSERT **insp)
+__col_insert_alloc(WT_SESSION_IMPL *session, uint64_t recno, WT_INSERT **insp)
 {
-	SESSION_BUFFER *sb;
+	WT_SESSION_BUFFER *sb;
 	WT_INSERT *ins;
 
 	/*
@@ -189,7 +190,8 @@ __col_insert_alloc(SESSION *session, uint64_t recno, WT_INSERT **insp)
  *	into a fixed-size file.
  */
 static int
-__col_wrong_fixed_size(SESSION *session, uint32_t len, uint32_t config_len)
+__col_wrong_fixed_size(
+    WT_SESSION_IMPL *session, uint32_t len, uint32_t config_len)
 {
 	__wt_errx(session,
 	    "%s: length of %lu does not match fixed-length file configuration "
diff --git a/src/btree/col_srch.c b/src/btree/col_srch.c
index cc1590d43d0..e99959f2b08 100644
--- a/src/btree/col_srch.c
+++ b/src/btree/col_srch.c
@@ -13,9 +13,9 @@
  *	Search a column-store tree for a specific record-based key.
  */
 int
-__wt_col_search(SESSION *session, uint64_t recno, uint32_t flags)
+__wt_col_search(WT_SESSION_IMPL *session, uint64_t recno, uint32_t flags)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_COL *cip;
 	WT_COL_REF *cref;
 	WT_INSERT *ins;
diff --git a/src/btree/row_get.c b/src/btree/row_get.c
index 2c012eeb852..65f6ba1ca21 100644
--- a/src/btree/row_get.c
+++ b/src/btree/row_get.c
@@ -12,9 +12,9 @@
  *	Db.row_get method.
  */
 int
-__wt_btree_row_get(SESSION *session, WT_ITEM *key, WT_ITEM *value)
+__wt_btree_row_get(WT_SESSION_IMPL *session, WT_ITEM *key, WT_ITEM *value)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	int ret;
 
 	btree = session->btree;
diff --git a/src/btree/row_key.c b/src/btree/row_key.c
index cab254bce0a..ed372405de8 100644
--- a/src/btree/row_key.c
+++ b/src/btree/row_key.c
@@ -15,7 +15,8 @@
  * is specified, instantiate the key into the in-memory page.
  */
 int
-__wt_row_key(SESSION *session, WT_PAGE *page, void *row_arg, WT_BUF *retb)
+__wt_row_key(
+    WT_SESSION_IMPL *session, WT_PAGE *page, void *row_arg, WT_BUF *retb)
 {
 	enum { FORWARD, BACKWARD } direction;
 	WT_BUF build, tmp;
@@ -266,7 +267,7 @@ err:	__wt_buf_free(session, &build);
  *	Server function to instantiate a key during a row-store search.
  */
 int
-__wt_row_key_serial_func(SESSION *session)
+__wt_row_key_serial_func(WT_SESSION_IMPL *session)
 {
 	WT_ROW *rip;
 	bitstr_t *ovfl;
diff --git a/src/btree/row_put.c b/src/btree/row_put.c
index 79309b44d1e..39ac919523d 100644
--- a/src/btree/row_put.c
+++ b/src/btree/row_put.c
@@ -8,14 +8,14 @@
 #include "wt_internal.h"
 #include "btree.i"
 
-static int __wt_row_update(SESSION *, WT_ITEM *, WT_ITEM *, int);
+static int __wt_row_update(WT_SESSION_IMPL *, WT_ITEM *, WT_ITEM *, int);
 
 /*
  * __wt_btree_row_del --
  *	Db.row_del method.
  */
 int
-__wt_btree_row_del(SESSION *session, WT_ITEM *key)
+__wt_btree_row_del(WT_SESSION_IMPL *session, WT_ITEM *key)
 {
 	int ret;
 
@@ -29,7 +29,7 @@ __wt_btree_row_del(SESSION *session, WT_ITEM *key)
  *	Db.row_put method.
  */
 int
-__wt_btree_row_put(SESSION *session, WT_ITEM *key, WT_ITEM *value)
+__wt_btree_row_put(WT_SESSION_IMPL *session, WT_ITEM *key, WT_ITEM *value)
 {
 	int ret;
 
@@ -43,7 +43,8 @@ __wt_btree_row_put(SESSION *session, WT_ITEM *key, WT_ITEM *value)
  *	Row-store delete and update.
  */
 static int
-__wt_row_update(SESSION *session, WT_ITEM *key, WT_ITEM *value, int is_write)
+__wt_row_update(
+    WT_SESSION_IMPL *session, WT_ITEM *key, WT_ITEM *value, int is_write)
 {
 	WT_INSERT **new_ins, *ins;
 	WT_PAGE *page;
@@ -137,13 +138,13 @@ err:		if (ins != NULL)
 
 /*
  * __wt_row_insert_alloc --
- *	Row-store insert: allocate a WT_INSERT structure from the SESSION's
+ *	Row-store insert: allocate a WT_INSERT structure from the session's
  *	buffer and fill it in.
  */
 int
-__wt_row_insert_alloc(SESSION *session, WT_ITEM *key, WT_INSERT **insp)
+__wt_row_insert_alloc(WT_SESSION_IMPL *session, WT_ITEM *key, WT_INSERT **insp)
 {
-	SESSION_BUFFER *sb;
+	WT_SESSION_BUFFER *sb;
 	WT_INSERT *ins;
 	uint32_t size;
 
@@ -168,7 +169,7 @@ __wt_row_insert_alloc(SESSION *session, WT_ITEM *key, WT_INSERT **insp)
  *	Server function to add an WT_INSERT entry to the page tree.
  */
 int
-__wt_insert_serial_func(SESSION *session)
+__wt_insert_serial_func(WT_SESSION_IMPL *session)
 {
 	WT_PAGE *page;
 	WT_INSERT **new_ins, **srch_ins, *ins;
@@ -212,13 +213,13 @@ err:	__wt_session_serialize_wrapup(session, page, 0);
 
 /*
  * __wt_update_alloc --
- *	Allocate a WT_UPDATE structure and associated value from the SESSION's
+ *	Allocate a WT_UPDATE structure and associated value from the session's
  *	buffer and fill it in.
  */
 int
-__wt_update_alloc(SESSION *session, WT_ITEM *value, WT_UPDATE **updp)
+__wt_update_alloc(WT_SESSION_IMPL *session, WT_ITEM *value, WT_UPDATE **updp)
 {
-	SESSION_BUFFER *sb;
+	WT_SESSION_BUFFER *sb;
 	WT_UPDATE *upd;
 	uint32_t size;
 
@@ -245,7 +246,7 @@ __wt_update_alloc(SESSION *session, WT_ITEM *value, WT_UPDATE **updp)
  *	Server function to add an WT_UPDATE entry in the page array.
  */
 int
-__wt_update_serial_func(SESSION *session)
+__wt_update_serial_func(WT_SESSION_IMPL *session)
 {
 	WT_PAGE *page;
 	WT_UPDATE **new_upd, **srch_upd, *upd;
diff --git a/src/btree/row_srch.c b/src/btree/row_srch.c
index 536e65bfd7c..7f681f52993 100644
--- a/src/btree/row_srch.c
+++ b/src/btree/row_srch.c
@@ -8,22 +8,22 @@
 #include "wt_internal.h"
 #include "btree.i"
 
-static inline int __wt_ins_search(SESSION *, WT_INSERT *, WT_ITEM *);
+static inline int __wt_ins_search(WT_SESSION_IMPL *, WT_INSERT *, WT_ITEM *);
 
 /*
  * __wt_row_search --
  *	Search a row-store tree for a specific key.
  */
 int
-__wt_row_search(SESSION *session, WT_ITEM *key, uint32_t flags)
+__wt_row_search(WT_SESSION_IMPL *session, WT_ITEM *key, uint32_t flags)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_INSERT *ins;
 	WT_PAGE *page;
 	WT_ROW *rip;
 	WT_ROW_REF *rref;
 	uint32_t base, indx, limit, slot, write_gen;
-	int cmp, ret, (*func)(BTREE *, const WT_ITEM *, const WT_ITEM *);
+	int cmp, ret, (*func)(WT_BTREE *, const WT_ITEM *, const WT_ITEM *);
 
 	session->srch_page = NULL;			/* Return values. */
 	session->srch_write_gen = 0;
@@ -245,11 +245,11 @@ err:	WT_PAGE_OUT(session, page);
  *	Search the slot's insert list.
  */
 static inline int
-__wt_ins_search(SESSION *session, WT_INSERT *ins, WT_ITEM *key)
+__wt_ins_search(WT_SESSION_IMPL *session, WT_INSERT *ins, WT_ITEM *key)
 {
 	WT_ITEM insert_key;
-	BTREE *btree;
-	int cmp, (*func)(BTREE *, const WT_ITEM *, const WT_ITEM *);
+	WT_BTREE *btree;
+	int cmp, (*func)(WT_BTREE *, const WT_ITEM *, const WT_ITEM *);
 
 	btree = session->btree;
 	func = btree->btree_compare;
diff --git a/src/db/db_stat.c b/src/db/db_stat.c
index 52e4b000cfd..564dd8af142 100644
--- a/src/db/db_stat.c
+++ b/src/db/db_stat.c
@@ -12,10 +12,10 @@
  *	Print DB handle statistics to a stream.
  */
 int
-__wt_btree_stat_print(SESSION *session, FILE *stream)
+__wt_btree_stat_print(WT_SESSION_IMPL *session, FILE *stream)
 {
-	BTREE *btree;
-	CONNECTION *conn;
+	WT_BTREE *btree;
+	WT_CONNECTION_IMPL *conn;
 
 	btree = session->btree;
 	conn = btree->conn;
@@ -70,7 +70,7 @@ __wt_btree_stat_print(SESSION *session, FILE *stream)
  *	Clear DB handle statistics.
  */
 int
-__wt_btree_stat_clear(BTREE *btree)
+__wt_btree_stat_clear(WT_BTREE *btree)
 {
 	__wt_stat_clear_btree_stats(btree->stats);
 	__wt_stat_clear_btree_file_stats(btree->fstats);
diff --git a/src/env/env_global.c b/src/env/env_global.c
index a032c731f88..bc2fa830995 100644
--- a/src/env/env_global.c
+++ b/src/env/env_global.c
@@ -47,7 +47,7 @@ int __wt_debugger_attach;
  *	A routine to wait for the debugging to attach.
  */
 void
-__wt_attach(SESSION *session)
+__wt_attach(WT_SESSION_IMPL *session)
 {
 #ifdef HAVE_ATTACH
 	__wt_err(session, 0,
diff --git a/src/env/env_handle.c b/src/env/env_handle.c
index d16fe8aebae..7b35a31c822 100644
--- a/src/env/env_handle.c
+++ b/src/env/env_handle.c
@@ -9,19 +9,19 @@
 
 /*
  * __wt_connection_config --
- *	Set configuration for a just-created CONNECTION handle.
+ *	Set configuration for a just-created WT_CONNECTION_IMPL handle.
  */
 int
-__wt_connection_config(CONNECTION *conn)
+__wt_connection_config(WT_CONNECTION_IMPL *conn)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 
 	session = &conn->default_session;
 
 						/* Global mutex */
-	WT_RET(__wt_mtx_alloc(session, "CONNECTION", 0, &conn->mtx));
+	WT_RET(__wt_mtx_alloc(session, "WT_CONNECTION_IMPL", 0, &conn->mtx));
 
-	TAILQ_INIT(&conn->dbqh);		/* BTREE list */
+	TAILQ_INIT(&conn->dbqh);		/* WT_BTREE list */
 	TAILQ_INIT(&conn->dlhqh);		/* Library list */
 	TAILQ_INIT(&conn->fhqh);		/* File list */
 
@@ -36,12 +36,12 @@ __wt_connection_config(CONNECTION *conn)
 
 /*
  * __wt_connection_destroy --
- *	Destroy the CONNECTION's underlying CONNECTION structure.
+ *	Destroy the connection's underlying WT_CONNECTION_IMPL structure.
  */
 int
-__wt_connection_destroy(CONNECTION *conn)
+__wt_connection_destroy(WT_CONNECTION_IMPL *conn)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	int ret;
 
 	session = &conn->default_session;
diff --git a/src/env/env_msg.c b/src/env/env_msg.c
index 2c4656dfb6e..c962fdad51e 100644
--- a/src/env/env_msg.c
+++ b/src/env/env_msg.c
@@ -12,7 +12,7 @@
  *	Initialize a WT_MBUF structure for message aggregation.
  */
 void
-__wt_mb_init(SESSION *session, WT_MBUF *mbp)
+__wt_mb_init(WT_SESSION_IMPL *session, WT_MBUF *mbp)
 {
 	mbp->session = session;
 	mbp->first = mbp->next = NULL;
diff --git a/src/env/env_open.c b/src/env/env_open.c
index a741b48577a..b8b471128a2 100644
--- a/src/env/env_open.c
+++ b/src/env/env_open.c
@@ -12,9 +12,9 @@
  *	Open a Env handle.
  */
 int
-__wt_connection_open(CONNECTION *conn, const char *home, mode_t mode)
+__wt_connection_open(WT_CONNECTION_IMPL *conn, const char *home, mode_t mode)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	int ret;
 
 	WT_UNUSED(home);
@@ -26,11 +26,11 @@ __wt_connection_open(CONNECTION *conn, const char *home, mode_t mode)
 	session = &conn->default_session;
 	ret = 0;
 
-	/* SESSION and hazard arrays. */
+	/* WT_SESSION_IMPL and hazard arrays. */
 	WT_RET(__wt_calloc(session,
-	    conn->session_size, sizeof(SESSION *), &conn->sessions));
+	    conn->session_size, sizeof(WT_SESSION_IMPL *), &conn->sessions));
 	WT_RET(__wt_calloc(session,
-	    conn->session_size, sizeof(SESSION), &conn->toc_array));
+	    conn->session_size, sizeof(WT_SESSION_IMPL), &conn->toc_array));
 	WT_RET(__wt_calloc(session,
 	   conn->session_size * conn->hazard_size, sizeof(WT_HAZARD),
 	   &conn->hazard));
@@ -59,10 +59,10 @@ err:	(void)__wt_connection_close(conn);
  *	Close a connection handle.
  */
 int
-__wt_connection_close(CONNECTION *conn)
+__wt_connection_close(WT_CONNECTION_IMPL *conn)
 {
-	BTREE *btree;
-	SESSION *session;
+	WT_BTREE *btree;
+	WT_SESSION_IMPL *session;
 	WT_DLH *dlh;
 	WT_FH *fh;
 	int ret, secondary_err;
@@ -70,7 +70,7 @@ __wt_connection_close(CONNECTION *conn)
 	session = &conn->default_session;
 	ret = secondary_err = 0;
 
-	/* Complain if BTREE handles weren't closed. */
+	/* Complain if WT_BTREE handles weren't closed. */
 	while ((btree = TAILQ_FIRST(&conn->dbqh)) != NULL) {
 		__wt_errx(session,
 		    "Connection has open btree handles: %s", btree->name);
diff --git a/src/env/env_session.c b/src/env/env_session.c
index c9b8a9a300e..a5bed0af6fa 100644
--- a/src/env/env_session.c
+++ b/src/env/env_session.c
@@ -9,12 +9,12 @@
 
 /*
  * __wt_connection_session --
- *	CONNECTION.session method.
+ *	WT_CONNECTION_IMPL.session method.
  */
 int
-__wt_connection_session(CONNECTION *conn, SESSION **sessionp)
+__wt_connection_session(WT_CONNECTION_IMPL *conn, WT_SESSION_IMPL **sessionp)
 {
-	SESSION *session;
+	WT_SESSION_IMPL *session;
 	uint32_t slot;
 
 	*sessionp = NULL;
@@ -57,19 +57,19 @@ __wt_connection_session(CONNECTION *conn, SESSION **sessionp)
 
 /*
  * __wt_session_close --
- *	SESSION.close method.
+ *	WT_SESSION_IMPL.close method.
  */
 int
-__wt_session_close(SESSION *session)
+__wt_session_close(WT_SESSION_IMPL *session)
 {
-	CONNECTION *conn;
-	SESSION **tp;
+	WT_CONNECTION_IMPL *conn;
+	WT_SESSION_IMPL **tp;
 	int ret;
 
 	conn = S2C(session);
 	ret = 0;
 
-	/* Unpin the current per-SESSION buffer. */
+	/* Unpin the current per-WT_SESSION_IMPL buffer. */
 	if (session->sb != NULL)
 		__wt_sb_decrement(session, session->sb);
 
@@ -102,17 +102,17 @@ __wt_session_close(SESSION *session)
 }
 
 #ifdef HAVE_DIAGNOSTIC
-static const char *__wt_session_print_state(SESSION *);
+static const char *__wt_session_print_state(WT_SESSION_IMPL *);
 
 /*
  * __wt_session_dump --
  *	Dump information about open sessions.
  */
 void
-__wt_session_dump(SESSION *session)
+__wt_session_dump(WT_SESSION_IMPL *session)
 {
-	CONNECTION *conn;
-	SESSION **tp;
+	WT_CONNECTION_IMPL *conn;
+	WT_SESSION_IMPL **tp;
 	WT_HAZARD *hp;
 	WT_MBUF mb;
 
@@ -156,10 +156,10 @@ __wt_session_dump(SESSION *session)
 
 /*
  * __wt_session_print_state --
- *	Return the SESSION state as a string.
+ *	Return the WT_SESSION_IMPL state as a string.
  */
 static const char *
-__wt_session_print_state(SESSION *session)
+__wt_session_print_state(WT_SESSION_IMPL *session)
 {
 	switch (session->wq_state) {
 	case WT_WORKQ_EVICT:
diff --git a/src/env/env_stat.c b/src/env/env_stat.c
index 8cfd1416dea..a84245797f1 100644
--- a/src/env/env_stat.c
+++ b/src/env/env_stat.c
@@ -9,15 +9,15 @@
 
 /*
  * __wt_connection_stat_print --
- *	Print CONNECTION handle statistics to a stream.
+ *	Print WT_CONNECTION_IMPL handle statistics to a stream.
  *
  * XXX this will become a statistics cursor.
  */
 int
-__wt_connection_stat_print(CONNECTION *conn, FILE *stream)
+__wt_connection_stat_print(WT_CONNECTION_IMPL *conn, FILE *stream)
 {
-	BTREE *btree;
-	SESSION *session;
+	WT_BTREE *btree;
+	WT_SESSION_IMPL *session;
 
 	session = &conn->default_session;
 
@@ -39,12 +39,12 @@ __wt_connection_stat_print(CONNECTION *conn, FILE *stream)
 
 /*
  * __wt_connection_stat_clear --
- *	Clear CONNECTION handle statistics.
+ *	Clear WT_CONNECTION_IMPL handle statistics.
  */
 int
-__wt_connection_stat_clear(CONNECTION *conn)
+__wt_connection_stat_clear(WT_CONNECTION_IMPL *conn)
 {
-	BTREE *btree;
+	WT_BTREE *btree;
 	int ret;
 
 	ret = 0;
diff --git a/src/env/env_workq.c b/src/env/env_workq.c
index b39be702d75..5759319bb76 100644
--- a/src/env/env_workq.c
+++ b/src/env/env_workq.c
@@ -9,18 +9,18 @@
 
 /*
  * __wt_workq_srvr --
- *      Routine to process the SESSION work queue.
+ *      Routine to process the WT_SESSION_IMPL work queue.
  */
 void *
 __wt_workq_srvr(void *arg)
 {
-	CONNECTION *conn;
-	SESSION **tp, *session;
+	WT_CONNECTION_IMPL *conn;
+	WT_SESSION_IMPL **tp, *session;
 	int call_evict, call_read, request;
 
-	conn = (CONNECTION *)arg;
+	conn = (WT_CONNECTION_IMPL *)arg;
 
-	/* Walk the SESSION list and execute requests. */
+	/* Walk the WT_SESSION_IMPL list and execute requests. */
 	while (F_ISSET(conn, WT_WORKQ_RUN)) {
 		++conn->api_gen;
 		WT_STAT_INCR(conn->stats, workq_passes);
diff --git a/src/include/api.h b/src/include/api.h
index dec988011f6..f3ee960ae03 100644
--- a/src/include/api.h
+++ b/src/include/api.h
@@ -8,7 +8,7 @@
 typedef struct {
 	WT_CURSOR iface;
 
-	BTREE *btree;
+	WT_BTREE *btree;
 	WT_WALK walk;
 	WT_PAGE *page;
 	WT_COL *cip;
@@ -78,9 +78,9 @@ typedef struct {
 	WT_CURSOR iface;
 } CURSOR_STAT;
 
-struct __btree {
-	CONNECTION *conn;		/* Enclosing connection */
-	TAILQ_ENTRY(__btree) q;		/* Linked list of files */
+struct __wt_btree {
+	WT_CONNECTION_IMPL *conn;	/* Enclosing connection */
+	TAILQ_ENTRY(__wt_btree) q;	/* Linked list of files */
 
 	uint32_t refcnt;		/* Sessions with this tree open. */
 
@@ -117,7 +117,7 @@ struct __btree {
 
 	int btree_compare_int;		/* Integer keys */
 					/* Comparison function */
-	int (*btree_compare)(BTREE *, const WT_ITEM *, const WT_ITEM *);
+	int (*btree_compare)(WT_BTREE *, const WT_ITEM *, const WT_ITEM *);
 
 	uint32_t intlitemsize;		/* Maximum item size for overflow */
 	uint32_t leafitemsize;
@@ -136,13 +136,13 @@ struct __btree {
 	uint32_t flags;
 };
 
-struct __btree_session {
-	BTREE *btree;
+struct __wt_btree_session {
+	WT_BTREE *btree;
 
 	const char *key_format;
 	const char *value_format;
 
-	TAILQ_ENTRY(__btree_session) q;
+	TAILQ_ENTRY(__wt_btree_session) q;
 };
 
 /*******************************************
@@ -165,21 +165,21 @@ struct __wt_hazard {
 #endif
 };
 
-struct __session {
+struct __wt_session_impl {
 	WT_SESSION iface;
 
 	WT_EVENT_HANDLER *event_handler;
 
-	TAILQ_ENTRY(__session) q;
+	TAILQ_ENTRY(__wt_session_impl) q;
 	TAILQ_HEAD(__cursors, wt_cursor) cursors;
 
-	TAILQ_HEAD(__btrees, __btree_session) btrees;
+	TAILQ_HEAD(__btrees, __wt_btree_session) btrees;
 
 	WT_MTX	 *mtx;			/* Blocking mutex */
 
 	const char *name;		/* Name */
 
-	BTREE	*btree;			/* Current file */
+	WT_BTREE *btree;		/* Current file */
 	WT_CURSOR *cursor;		/* Current cursor */
 
 	WT_BUF	**scratch;		/* Temporary memory for any function */
@@ -188,16 +188,16 @@ struct __session {
 	WT_BUF	logrec_buf;		/* Buffer for log records */
 	WT_BUF	logprint_buf;		/* Buffer for debug log records */
 
-					/* SESSION workQ request */
+					/* WT_SESSION_IMPL workQ request */
 	wq_state_t volatile wq_state;	/* Request state */
 	int	  wq_ret;		/* Return value */
-	int     (*wq_func)(SESSION *);	/* Function */
+	int     (*wq_func)(WT_SESSION_IMPL *);	/* Function */
 	void	 *wq_args;		/* Function argument */
 	int	  wq_sleeping;		/* Thread is blocked */
 
 	WT_HAZARD *hazard;		/* Hazard reference array */
 
-	SESSION_BUFFER *sb;		/* Per-thread update buffer */
+	WT_SESSION_BUFFER *sb;		/* Per-thread update buffer */
 	uint32_t update_alloc_size;	/* Allocation size */
 
 					/* Search return values: */
@@ -210,7 +210,7 @@ struct __session {
 	WT_UPDATE      **srch_upd;	/* WT_UPDATE insert node */
 	uint32_t	 srch_slot;	/* WT_INSERT/WT_UPDATE slot */
 
-	void (*msgcall)(const CONNECTION *, const char *);
+	void (*msgcall)(const WT_CONNECTION_IMPL *, const char *);
 
 	FILE *msgfile;
 
@@ -220,12 +220,12 @@ struct __session {
 /*******************************************
  * Implementation of WT_CONNECTION
  *******************************************/
-struct __connection {
+struct __wt_connection_impl {
 	WT_CONNECTION iface;
 
 	const char *home;
 
-	SESSION default_session;	/* For operations without an
+	WT_SESSION_IMPL default_session;/* For operations without an
 					   application-supplied session. */
 
 	WT_MTX *mtx;			/* Global mutex */
@@ -234,7 +234,7 @@ struct __connection {
 	pthread_t cache_evict_tid;	/* Cache eviction server thread ID */
 	pthread_t cache_read_tid;	/* Cache read server thread ID */
 
-	TAILQ_HEAD(wt_btree_qh, __btree) dbqh; /* Locked: database list */
+	TAILQ_HEAD(wt_btree_qh, __wt_btree) dbqh; /* Locked: database list */
 	u_int dbqcnt;			/* Locked: database list count */
 
 	TAILQ_HEAD(
@@ -252,16 +252,16 @@ struct __connection {
 	 * needs more.   Growing the number of threads dynamically is possible,
 	 * but tricky since the workQ is walking the array without locking it.
 	 *
-	 * There's an array of SESSION pointers that reference the allocated
+	 * There's an array of WT_SESSION_IMPL pointers that reference the allocated
 	 * array; we do it that way because we want an easy way for the workQ
 	 * code to avoid walking the entire array when only a few threads are
 	 * running.
 	 */
-	SESSION	**sessions;		/* TOC reference */
+	WT_SESSION_IMPL	**sessions;		/* TOC reference */
 	uint32_t toc_cnt;		/* TOC count */
 	void	 *toc_array;		/* TOC array */
 
-	TAILQ_HEAD(__sessions, __session) sessions_head;
+	TAILQ_HEAD(__sessions, __wt_session_impl) sessions_head;
 
 	/*
 	 * WiredTiger allocates space for 15 hazard references in each thread of
@@ -271,7 +271,7 @@ struct __connection {
 	 * the right change is to increase the default).  The method is there
 	 * just in case an application starts failing in the field.
 	 *
-	 * The hazard array is separate from the SESSION array because we must
+	 * The hazard array is separate from the WT_SESSION_IMPL array because we must
 	 * be able to easily copy and search it when evicting pages from the
 	 * cache.
 	 */
@@ -292,7 +292,7 @@ struct __connection {
 
 	uint32_t hazard_size;
 
-	void (*msgcall)(const CONNECTION *, const char *);
+	void (*msgcall)(const WT_CONNECTION_IMPL *, const char *);
 
 	FILE *msgfile;
 
@@ -330,22 +330,16 @@ struct __connection {
 	API_CALL(s, connection, n, NULL, NULL, cfg);			\
 
 #define	CURSOR_API_CALL(cur, s, n, bt)					\
-	(s) = (SESSION *)(cur)->session;				\
+	(s) = (WT_SESSION_IMPL *)(cur)->session;				\
 	API_CALL_NOCONF(s, cursor, n, (cur), bt);			\
 
 #define	CURSOR_API_CALL_CONF(cur, s, n, bt, cfg)			\
-	(s) = (SESSION *)(cur)->session;				\
+	(s) = (WT_SESSION_IMPL *)(cur)->session;				\
 	API_CALL(s, cursor, n, cur, bt, cfg);				\
 
 /*******************************************
- * Prototypes.
+ * Global variables.
  *******************************************/
-int	 wiredtiger_env_init(CONNECTION **, uint32_t);
-void	 wiredtiger_err_stream(FILE *);
-int	 wiredtiger_simple_setup(
-    const char *, WT_EVENT_HANDLER *, const char *, BTREE **);
-int	 wiredtiger_simple_teardown(const char *, BTREE *);
-
 extern WT_EVENT_HANDLER *__wt_event_handler_default;
 extern WT_EVENT_HANDLER *__wt_event_handler_verbose;
 
diff --git a/src/include/btree.h b/src/include/btree.h
index baac4820e03..16a6faa6e46 100644
--- a/src/include/btree.h
+++ b/src/include/btree.h
@@ -621,7 +621,7 @@ struct __wt_col {
  * list.
  */
 struct __wt_update {
-	SESSION_BUFFER *sb;		/* session buffer holding this update */
+	WT_SESSION_BUFFER *sb;		/* session buffer holding this update */
 
 	WT_UPDATE *next;		/* forward-linked list */
 
@@ -670,7 +670,7 @@ struct __wt_update {
  * scale and it isn't useful enough to re-implement, IMNSHO.)
  */
 struct __wt_insert {
-	SESSION_BUFFER *sb;		/* session buffer holding this update */
+	WT_SESSION_BUFFER *sb;		/* session buffer holding this update */
 
 	WT_INSERT *next;		/* forward-linked list */
 
diff --git a/src/include/btree.i b/src/include/btree.i
index 28defcb9a13..844e76c772e 100644
--- a/src/include/btree.i
+++ b/src/include/btree.i
@@ -10,7 +10,7 @@
  *	Read pages into the cache.
  */
 static inline void
-__wt_cache_page_in(SESSION *session, WT_PAGE *page, uint32_t size)
+__wt_cache_page_in(WT_SESSION_IMPL *session, WT_PAGE *page, uint32_t size)
 {
 	WT_CACHE *cache;
 
@@ -26,7 +26,7 @@ __wt_cache_page_in(SESSION *session, WT_PAGE *page, uint32_t size)
  *	Discard pages from the cache.
  */
 static inline void
-__wt_cache_page_out(SESSION *session, WT_PAGE *page, uint32_t size)
+__wt_cache_page_out(WT_SESSION_IMPL *session, WT_PAGE *page, uint32_t size)
 {
 	WT_CACHE *cache;
 
@@ -43,7 +43,7 @@ __wt_cache_page_out(SESSION *session, WT_PAGE *page, uint32_t size)
 }
 
 static inline uint64_t
-__wt_cache_read_gen(SESSION *session)
+__wt_cache_read_gen(WT_SESSION_IMPL *session)
 {
 	return (++S2C(session)->cache->read_gen);
 }
diff --git a/src/include/cache.h b/src/include/cache.h
index ea07dad740b..dcdef44b62a 100644
--- a/src/include/cache.h
+++ b/src/include/cache.h
@@ -14,8 +14,8 @@ extern "C" {
  *	Encapsulation of an eviction candidate.
  */
 struct __wt_evict_list {
-	WT_PAGE	*page;				/* Page */
-	BTREE	*btree;				/* Underlying file object */
+	WT_PAGE	 *page;				/* Page */
+	WT_BTREE *btree;			/* Underlying file object */
 };
 
 /*
@@ -23,9 +23,9 @@ struct __wt_evict_list {
  *	Encapsulation of a eviction request.
  */
 struct __wt_evict_req {
-	SESSION *session;			/* Requesting thread */
-	BTREE	*btree;				/* Btree */
-	int	 close_method;			/* Discard pages */
+	WT_SESSION_IMPL *session;			/* Requesting thread */
+	WT_BTREE *btree;				/* Btree */
+	int	  close_method;			/* Discard pages */
 
 	WT_PAGE **retry;			/* Pages to retry */
 	uint32_t  retry_next;			/* Next retry slot */
@@ -38,7 +38,7 @@ struct __wt_evict_req {
  *	Encapsulation of a read request.
  */
 struct __wt_read_req {
-	SESSION *session;			/* Requesting thread */
+	WT_SESSION_IMPL *session;			/* Requesting thread */
 	WT_PAGE *parent;			/* Parent */
 	WT_REF  *ref;				/* Reference/Address */
 	int	 dsk_verify;			/* Verify the disk image */
diff --git a/src/include/debug.h b/src/include/debug.h
index a9984ee04be..5748d1f283b 100644
--- a/src/include/debug.h
+++ b/src/include/debug.h
@@ -28,7 +28,7 @@ extern "C" {
  * dump them to the application's logging file/function.
  */
 typedef struct __wt_mbuf {
-	SESSION	 *session;		/* Enclosing environment */
+	WT_SESSION_IMPL	 *session;		/* Enclosing environment */
 
 	char  *first;			/* Allocated message buffer */
 	char  *next;			/* Next available byte of the buffer */
diff --git a/src/include/extern.h b/src/include/extern.h
index 886179c05b1..5ebb45a7c70 100644
--- a/src/include/extern.h
+++ b/src/include/extern.h
@@ -24,13 +24,13 @@ int __wt_config_gets(const char **cfg, const char *key, WT_CONFIG_ITEM *value);
  int __wt_config_getones(const char *cfg,
     const char *key,
     WT_CONFIG_ITEM *value);
-int __wt_config_checklist(SESSION *session,
+int __wt_config_checklist(WT_SESSION_IMPL *session,
     const char **defaults,
     const char *config);
-int __wt_config_check(SESSION *session,
+int __wt_config_check( WT_SESSION_IMPL *session,
     const char *defaults,
     const char *config);
-int __wt_config_collapse(SESSION *session,
+int __wt_config_collapse(WT_SESSION_IMPL *session,
     const char **cfg,
     const char **config_ret);
 const char *__wt_confdfl_connection_add_collator;
@@ -56,40 +56,42 @@ const char *__wt_confdfl_session_sync;
 const char *__wt_confdfl_session_truncate;
 const char *__wt_confdfl_session_verify;
 const char *__wt_confdfl_wiredtiger_open;
-int __wt_curbtree_open(SESSION *session,
+int __wt_curbtree_open(WT_SESSION_IMPL *session,
     const char *uri,
     const char *config,
     WT_CURSOR **cursorp);
 int __wt_curbulk_init(CURSOR_BULK *cbulk);
-int __wt_curconfig_open(SESSION *session,
+int __wt_curconfig_open(WT_SESSION_IMPL *session,
     const char *uri,
     const char *config,
     WT_CURSOR **cursorp);
 void __wt_curdump_init(WT_CURSOR *cursor, int printable);
-int __wt_curstat_open(SESSION *session,
+int __wt_curstat_open(WT_SESSION_IMPL *session,
     const char *uri,
     const char *config,
     WT_CURSOR **cursorp);
 int __wt_cursor_close(WT_CURSOR *cursor, const char *config);
 void __wt_cursor_init(WT_CURSOR *cursor, const char *config);
-int __wt_session_add_btree(SESSION *session, BTREE_SESSION **btree_sessionp);
-int __wt_session_get_btree(SESSION *session,
+int __wt_session_add_btree( WT_SESSION_IMPL *session,
+    WT_BTREE_SESSION **btree_sessionp);
+int __wt_session_get_btree(WT_SESSION_IMPL *session,
     const char *name,
     size_t namelen,
-    BTREE_SESSION **btree_sessionp);
-int __wt_session_remove_btree(SESSION *session, BTREE_SESSION *btree_session);
-int __wt_block_alloc(SESSION *session, uint32_t *addrp, uint32_t size);
-int __wt_block_free(SESSION *session, uint32_t addr, uint32_t size);
-int __wt_block_read(SESSION *session);
-int __wt_block_write(SESSION *session);
-void __wt_block_discard(SESSION *session);
-void __wt_block_dump(SESSION *session);
+    WT_BTREE_SESSION **btree_sessionp);
+int __wt_session_remove_btree( WT_SESSION_IMPL *session,
+    WT_BTREE_SESSION *btree_session);
+int __wt_block_alloc(WT_SESSION_IMPL *session, uint32_t *addrp, uint32_t size);
+int __wt_block_free(WT_SESSION_IMPL *session, uint32_t addr, uint32_t size);
+int __wt_block_read(WT_SESSION_IMPL *session);
+int __wt_block_write(WT_SESSION_IMPL *session);
+void __wt_block_discard(WT_SESSION_IMPL *session);
+void __wt_block_dump(WT_SESSION_IMPL *session);
 int __wt_bulk_init(CURSOR_BULK *cbulk);
 int __wt_bulk_insert(CURSOR_BULK *cbulk);
 int __wt_bulk_end(CURSOR_BULK *cbulk);
-int __wt_cache_create(CONNECTION *conn);
-void __wt_cache_stats_update(CONNECTION *conn);
-void __wt_cache_destroy(CONNECTION *conn);
+int __wt_cache_create(WT_CONNECTION_IMPL *conn);
+void __wt_cache_stats_update(WT_CONNECTION_IMPL *conn);
+void __wt_cache_destroy(WT_CONNECTION_IMPL *conn);
 void __wt_cell_set(WT_CELL *cell,
     u_int type,
     u_int prefix,
@@ -98,11 +100,11 @@ void __wt_cell_set(WT_CELL *cell,
 void *__wt_cell_data(WT_CELL *cell);
 uint32_t __wt_cell_datalen(WT_CELL *cell);
 uint32_t __wt_cell_len(WT_CELL *cell);
-int __wt_cell_copy(SESSION *session, WT_CELL *cell, WT_BUF *retb);
-int __wt_bt_lex_compare( BTREE *btree,
+int __wt_cell_copy(WT_SESSION_IMPL *session, WT_CELL *cell, WT_BUF *retb);
+int __wt_bt_lex_compare( WT_BTREE *btree,
     const WT_ITEM *user_item,
     const WT_ITEM *tree_item);
-int __wt_bt_int_compare( BTREE *btree,
+int __wt_bt_int_compare( WT_BTREE *btree,
     const WT_ITEM *user_item,
     const WT_ITEM *tree_item);
 int __wt_btcur_first(CURSOR_BTREE *cbt);
@@ -113,183 +115,206 @@ int __wt_btcur_insert(CURSOR_BTREE *cbt);
 int __wt_btcur_update(CURSOR_BTREE *cbt);
 int __wt_btcur_remove(CURSOR_BTREE *cbt);
 int __wt_btcur_close(CURSOR_BTREE *cbt, const char *config);
-int __wt_debug_dump(SESSION *session, const char *ofile, FILE *fp);
-int __wt_debug_addr( SESSION *session,
+int __wt_debug_dump(WT_SESSION_IMPL *session, const char *ofile, FILE *fp);
+int __wt_debug_addr(WT_SESSION_IMPL *session,
     uint32_t addr,
     uint32_t size,
     const char *ofile,
     FILE *fp);
-int __wt_debug_disk( SESSION *session,
+int __wt_debug_disk( WT_SESSION_IMPL *session,
     WT_PAGE_DISK *dsk,
     const char *ofile,
     FILE *fp);
-int __wt_debug_tree_all( SESSION *session,
+int __wt_debug_tree_all( WT_SESSION_IMPL *session,
     WT_PAGE *page,
     const char *ofile,
     FILE *fp);
-int __wt_debug_tree(SESSION *session,
+int __wt_debug_tree( WT_SESSION_IMPL *session,
     WT_PAGE *page,
     const char *ofile,
     FILE *fp);
-int __wt_debug_page(SESSION *session,
+int __wt_debug_page( WT_SESSION_IMPL *session,
     WT_PAGE *page,
     const char *ofile,
     FILE *fp);
 void __wt_debug_item(const char *tag, void *arg_item, FILE *fp);
-int __wt_desc_read(SESSION *session);
-int __wt_desc_write(SESSION *session, const char *config, WT_FH *fh);
-int __wt_desc_update(SESSION *session);
-void __wt_page_free( SESSION *session,
+int __wt_desc_read(WT_SESSION_IMPL *session);
+int __wt_desc_write(WT_SESSION_IMPL *session, const char *config, WT_FH *fh);
+int __wt_desc_update(WT_SESSION_IMPL *session);
+void __wt_page_free( WT_SESSION_IMPL *session,
     WT_PAGE *page,
     uint32_t addr,
     uint32_t size);
-int __wt_btree_dump(SESSION *session, FILE *stream, uint32_t flags);
+int __wt_btree_dump(WT_SESSION_IMPL *session, FILE *stream, uint32_t flags);
 void __wt_print_byte_string(const uint8_t *data, uint32_t size, FILE *stream);
-void __wt_workq_evict_server(CONNECTION *conn, int force);
-int __wt_evict_file_serial_func(SESSION *session);
+void __wt_workq_evict_server(WT_CONNECTION_IMPL *conn, int force);
+int __wt_evict_file_serial_func(WT_SESSION_IMPL *session);
 void *__wt_cache_evict_server(void *arg);
-void __wt_workq_evict_server_exit(CONNECTION *conn);
-int __wt_btree_create(SESSION *session, const char *name, const char *config);
-int __wt_btree_open(SESSION *session, const char *name, uint32_t flags);
-int __wt_btree_close(SESSION *session);
-int __wt_btree_huffman_open(SESSION *session);
-void __wt_btree_huffman_close(SESSION *session);
+void __wt_workq_evict_server_exit(WT_CONNECTION_IMPL *conn);
+int __wt_btree_create( WT_SESSION_IMPL *session,
+    const char *name,
+    const char *config);
+int __wt_btree_open(WT_SESSION_IMPL *session, const char *name, uint32_t flags);
+int __wt_btree_close(WT_SESSION_IMPL *session);
+int __wt_btree_huffman_open(WT_SESSION_IMPL *session);
+void __wt_btree_huffman_close(WT_SESSION_IMPL *session);
 const char *__wt_page_type_string(u_int type);
 const char *__wt_cell_type_string(WT_CELL *cell);
-int __wt_ovfl_in(SESSION *session, WT_OFF *ovfl, WT_BUF *store);
+int __wt_ovfl_in(WT_SESSION_IMPL *session, WT_OFF *ovfl, WT_BUF *store);
 int
-__wt_page_in_func(SESSION *session, WT_PAGE *parent, WT_REF *ref, int dsk_verify
+__wt_page_in_func(
+ WT_SESSION_IMPL *session, WT_PAGE *parent, WT_REF *ref, int dsk_verify
 #ifdef HAVE_DIAGNOSTIC
  , const char *file, int line
 #endif
  );
-int __wt_page_inmem(SESSION *session,
+int __wt_page_inmem(WT_SESSION_IMPL *session,
     WT_PAGE *parent,
     WT_REF *parent_ref,
     WT_PAGE_DISK *dsk,
     WT_PAGE **pagep);
-void __wt_workq_read_server(CONNECTION *conn, int force);
-int __wt_cache_read_serial_func(SESSION *session);
+void __wt_workq_read_server(WT_CONNECTION_IMPL *conn, int force);
+int __wt_cache_read_serial_func(WT_SESSION_IMPL *session);
 void *__wt_cache_read_server(void *arg);
-void __wt_workq_read_server_exit(CONNECTION *conn);
-void __wt_rec_destroy(SESSION *session);
-int __wt_page_reconcile( SESSION *session,
+void __wt_workq_read_server_exit(WT_CONNECTION_IMPL *conn);
+void __wt_rec_destroy(WT_SESSION_IMPL *session);
+int __wt_page_reconcile( WT_SESSION_IMPL *session,
     WT_PAGE *page,
     uint32_t slvg_skip,
     uint32_t flags);
-int __wt_return_data(SESSION *session,
+int __wt_return_data( WT_SESSION_IMPL *session,
     WT_ITEM *key,
     WT_ITEM *value,
     int key_return);
-int __wt_disk_read( SESSION *session,
+int __wt_disk_read( WT_SESSION_IMPL *session,
     WT_PAGE_DISK *dsk,
     uint32_t addr,
     uint32_t size);
-int __wt_disk_write( SESSION *session,
+int __wt_disk_write( WT_SESSION_IMPL *session,
     WT_PAGE_DISK *dsk,
     uint32_t addr,
     uint32_t size);
-int __wt_salvage(SESSION *session, const char *config);
+int __wt_salvage(WT_SESSION_IMPL *session, const char *config);
 void __wt_trk_dump(const char *l, void *ss_arg);
-int __wt_page_stat(SESSION *session, WT_PAGE *page, void *arg);
-int __wt_bt_sync(SESSION *session);
-int __wt_verify(SESSION *session, FILE *stream, const char *config);
-int __wt_verify_dsk_page( SESSION *session,
+int __wt_page_stat(WT_SESSION_IMPL *session, WT_PAGE *page, void *arg);
+int __wt_bt_sync(WT_SESSION_IMPL *session);
+int __wt_verify(WT_SESSION_IMPL *session, FILE *stream, const char *config);
+int __wt_verify_dsk_page( WT_SESSION_IMPL *session,
     WT_PAGE_DISK *dsk,
     uint32_t addr,
     uint32_t size);
-int __wt_verify_dsk_chunk( SESSION *session,
+int __wt_verify_dsk_chunk( WT_SESSION_IMPL *session,
     WT_PAGE_DISK *dsk,
     uint32_t addr,
     uint32_t size);
-int __wt_tree_walk(SESSION *session,
+int __wt_tree_walk(WT_SESSION_IMPL *session,
     WT_PAGE *page,
-    int (*work)(SESSION *,
+    int (*work)(WT_SESSION_IMPL *,
     WT_PAGE *,
     void *),
     void *arg);
-int __wt_walk_begin(SESSION *session,
+int __wt_walk_begin( WT_SESSION_IMPL *session,
     WT_PAGE *page,
     WT_WALK *walk,
     uint32_t flags);
-void __wt_walk_end(SESSION *session, WT_WALK *walk);
-int __wt_walk_next(SESSION *session, WT_WALK *walk, WT_PAGE **pagep);
-int __wt_btree_col_get(SESSION *session, uint64_t recno, WT_ITEM *value);
-int __wt_btree_col_del(SESSION *session, uint64_t recno);
-int __wt_btree_col_put(SESSION *session, uint64_t recno, WT_ITEM *value);
-int __wt_col_search(SESSION *session, uint64_t recno, uint32_t flags);
-int __wt_btree_row_get(SESSION *session, WT_ITEM *key, WT_ITEM *value);
-int __wt_row_key(SESSION *session, WT_PAGE *page, void *row_arg, WT_BUF *retb);
-int __wt_row_key_serial_func(SESSION *session);
-int __wt_btree_row_del(SESSION *session, WT_ITEM *key);
-int __wt_btree_row_put(SESSION *session, WT_ITEM *key, WT_ITEM *value);
-int __wt_row_insert_alloc(SESSION *session, WT_ITEM *key, WT_INSERT **insp);
-int __wt_insert_serial_func(SESSION *session);
-int __wt_update_alloc(SESSION *session, WT_ITEM *value, WT_UPDATE **updp);
-int __wt_update_serial_func(SESSION *session);
-int __wt_row_search(SESSION *session, WT_ITEM *key, uint32_t flags);
-int __wt_btree_stat_print(SESSION *session, FILE *stream);
-int __wt_btree_stat_clear(BTREE *btree);
+void __wt_walk_end(WT_SESSION_IMPL *session, WT_WALK *walk);
+int __wt_walk_next(WT_SESSION_IMPL *session, WT_WALK *walk, WT_PAGE **pagep);
+int __wt_btree_col_get(WT_SESSION_IMPL *session,
+    uint64_t recno,
+    WT_ITEM *value);
+int __wt_btree_col_del(WT_SESSION_IMPL *session, uint64_t recno);
+int __wt_btree_col_put(WT_SESSION_IMPL *session,
+    uint64_t recno,
+    WT_ITEM *value);
+int __wt_col_search(WT_SESSION_IMPL *session, uint64_t recno, uint32_t flags);
+int __wt_btree_row_get(WT_SESSION_IMPL *session, WT_ITEM *key, WT_ITEM *value);
+int __wt_row_key( WT_SESSION_IMPL *session,
+    WT_PAGE *page,
+    void *row_arg,
+    WT_BUF *retb);
+int __wt_row_key_serial_func(WT_SESSION_IMPL *session);
+int __wt_btree_row_del(WT_SESSION_IMPL *session, WT_ITEM *key);
+int __wt_btree_row_put(WT_SESSION_IMPL *session, WT_ITEM *key, WT_ITEM *value);
+int __wt_row_insert_alloc(WT_SESSION_IMPL *session,
+    WT_ITEM *key,
+    WT_INSERT **insp);
+int __wt_insert_serial_func(WT_SESSION_IMPL *session);
+int __wt_update_alloc(WT_SESSION_IMPL *session,
+    WT_ITEM *value,
+    WT_UPDATE **updp);
+int __wt_update_serial_func(WT_SESSION_IMPL *session);
+int __wt_row_search(WT_SESSION_IMPL *session, WT_ITEM *key, uint32_t flags);
+int __wt_btree_stat_print(WT_SESSION_IMPL *session, FILE *stream);
+int __wt_btree_stat_clear(WT_BTREE *btree);
 int __wt_library_init(void);
 int __wt_breakpoint(void);
-void __wt_attach(SESSION *session);
-int __wt_connection_config(CONNECTION *conn);
-int __wt_connection_destroy(CONNECTION *conn);
-void __wt_mb_init(SESSION *session, WT_MBUF *mbp);
+void __wt_attach(WT_SESSION_IMPL *session);
+int __wt_connection_config(WT_CONNECTION_IMPL *conn);
+int __wt_connection_destroy(WT_CONNECTION_IMPL *conn);
+void __wt_mb_init(WT_SESSION_IMPL *session, WT_MBUF *mbp);
 void __wt_mb_discard(WT_MBUF *mbp);
 void __wt_mb_add(WT_MBUF *mbp, const char *fmt, ...);
 void __wt_mb_write(WT_MBUF *mbp);
-int __wt_connection_open(CONNECTION *conn, const char *home, mode_t mode);
-int __wt_connection_close(CONNECTION *conn);
-int __wt_connection_session(CONNECTION *conn, SESSION **sessionp);
-int __wt_session_close(SESSION *session);
-void __wt_session_dump(SESSION *session);
-int __wt_connection_stat_print(CONNECTION *conn, FILE *stream);
-int __wt_connection_stat_clear(CONNECTION *conn);
+int __wt_connection_open(WT_CONNECTION_IMPL *conn,
+    const char *home,
+    mode_t mode);
+int __wt_connection_close(WT_CONNECTION_IMPL *conn);
+int __wt_connection_session(WT_CONNECTION_IMPL *conn,
+    WT_SESSION_IMPL **sessionp);
+int __wt_session_close(WT_SESSION_IMPL *session);
+void __wt_session_dump(WT_SESSION_IMPL *session);
+int __wt_connection_stat_print(WT_CONNECTION_IMPL *conn, FILE *stream);
+int __wt_connection_stat_clear(WT_CONNECTION_IMPL *conn);
 void __wt_stat_print(WT_STATS *s, FILE *stream);
 void *__wt_workq_srvr(void *arg);
-int __wt_log_put(SESSION *session, WT_LOGREC_DESC *recdesc, ...);
-int __wt_log_vprintf(SESSION *session, const char *fmt, va_list ap);
-int __wt_log_printf(SESSION *session,
+int __wt_log_put(WT_SESSION_IMPL *session, WT_LOGREC_DESC *recdesc, ...);
+int __wt_log_vprintf(WT_SESSION_IMPL *session, const char *fmt, va_list ap);
+int __wt_log_printf(WT_SESSION_IMPL *session,
     const char *fmt,
     ...) WT_GCC_ATTRIBUTE ((format (printf,
     2,
     3)));
 WT_LOGREC_DESC __wt_logdesc_debug;
-void __wt_abort(SESSION *session);
-int __wt_calloc(SESSION *session, size_t number, size_t size, void *retp);
-int __wt_realloc(SESSION *session,
+void __wt_abort(WT_SESSION_IMPL *session);
+int __wt_calloc(WT_SESSION_IMPL *session,
+    size_t number,
+    size_t size,
+    void *retp);
+int __wt_realloc(WT_SESSION_IMPL *session,
     uint32_t *bytes_allocated_ret,
     size_t bytes_to_allocate,
     void *retp);
-int __wt_strdup(SESSION *session, const char *str, void *retp);
-void __wt_free_int(SESSION *session, void *p_arg);
-int __wt_dlopen(SESSION *session, const char *path, WT_DLH **dlhp);
-int __wt_dlsym(SESSION *session, WT_DLH *dlh, const char *name, void **sym_ret);
-int __wt_dlclose(SESSION *session, WT_DLH *dlh);
+int __wt_strdup(WT_SESSION_IMPL *session, const char *str, void *retp);
+void __wt_free_int(WT_SESSION_IMPL *session, void *p_arg);
+int __wt_dlopen(WT_SESSION_IMPL *session, const char *path, WT_DLH **dlhp);
+int __wt_dlsym(WT_SESSION_IMPL *session,
+    WT_DLH *dlh,
+    const char *name,
+    void **sym_ret);
+int __wt_dlclose(WT_SESSION_IMPL *session, WT_DLH *dlh);
 int __wt_exist(const char *path);
-int __wt_filesize(SESSION *session, WT_FH *fh, off_t *sizep);
-int __wt_fsync(SESSION *session, WT_FH *fh);
-int __wt_ftruncate(SESSION *session, WT_FH *fh, off_t len);
-int __wt_mtx_alloc(SESSION *session,
+int __wt_filesize(WT_SESSION_IMPL *session, WT_FH *fh, off_t *sizep);
+int __wt_fsync(WT_SESSION_IMPL *session, WT_FH *fh);
+int __wt_ftruncate(WT_SESSION_IMPL *session, WT_FH *fh, off_t len);
+int __wt_mtx_alloc(WT_SESSION_IMPL *session,
     const char *name,
     int is_locked,
     WT_MTX **mtxp);
-void __wt_lock(SESSION *session, WT_MTX *mtx);
-void __wt_unlock(SESSION *session, WT_MTX *mtx);
-int __wt_mtx_destroy(SESSION *session, WT_MTX *mtx);
-int __wt_open( SESSION *session,
+void __wt_lock(WT_SESSION_IMPL *session, WT_MTX *mtx);
+void __wt_unlock(WT_SESSION_IMPL *session, WT_MTX *mtx);
+int __wt_mtx_destroy(WT_SESSION_IMPL *session, WT_MTX *mtx);
+int __wt_open(WT_SESSION_IMPL *session,
     const char *name,
     mode_t mode,
     int ok_create,
     WT_FH **fhp);
-int __wt_close(SESSION *session, WT_FH *fh);
-int __wt_read(SESSION *session,
+int __wt_close(WT_SESSION_IMPL *session, WT_FH *fh);
+int __wt_read(WT_SESSION_IMPL *session,
     WT_FH *fh,
     off_t offset,
     uint32_t bytes,
     void *buf);
-int __wt_write(SESSION *session,
+int __wt_write(WT_SESSION_IMPL *session,
     WT_FH *fh,
     off_t offset,
     uint32_t bytes,
@@ -299,61 +324,61 @@ int __wt_thread_create(pthread_t *tidret, void *(*func)(void *), void *arg);
 void __wt_thread_join(pthread_t tid);
 void __wt_yield(void);
 uint32_t __wt_cksum(const void *chunk, size_t len);
-void __wt_errv(SESSION *session,
+void __wt_errv(WT_SESSION_IMPL *session,
     int error,
     const char *prefix1,
     const char *prefix2,
     const char *fmt,
     va_list ap);
-void __wt_err(SESSION *session,
+void __wt_err(WT_SESSION_IMPL *session,
     int error,
     const char *fmt,
     ...) WT_GCC_ATTRIBUTE ((format (printf,
     3,
     4)));
-void __wt_errx(SESSION *session,
+void __wt_errx(WT_SESSION_IMPL *session,
     const char *fmt,
     ...) WT_GCC_ATTRIBUTE ((format (printf,
     2,
     3)));
-void __wt_msgv(SESSION *session,
+void __wt_msgv(WT_SESSION_IMPL *session,
     const char *prefix1,
     const char *prefix2,
     const char *fmt,
     va_list ap);
-void __wt_msg(SESSION *session,
+void __wt_msg(WT_SESSION_IMPL *session,
     const char *fmt,
     ...) WT_GCC_ATTRIBUTE ((format (printf,
     2,
     3)));
-void __wt_assert( SESSION *session,
+void __wt_assert( WT_SESSION_IMPL *session,
     const char *check,
     const char *file_name,
     int line_number);
-int __wt_file_format(SESSION *session);
-int __wt_file_item_too_big(SESSION *session);
+int __wt_file_format(WT_SESSION_IMPL *session);
+int __wt_file_item_too_big(WT_SESSION_IMPL *session);
 int
-__wt_hazard_set(SESSION *session, WT_REF *ref
+__wt_hazard_set(WT_SESSION_IMPL *session, WT_REF *ref
 #ifdef HAVE_DIAGNOSTIC
  , const char *file, int line
 #endif
  );
-void __wt_hazard_clear(SESSION *session, WT_PAGE *page);
-void __wt_hazard_empty(SESSION *session, const char *name);
-void __wt_hazard_validate(SESSION *session, WT_PAGE *page);
-int __wt_huffman_open(SESSION *session,
+void __wt_hazard_clear(WT_SESSION_IMPL *session, WT_PAGE *page);
+void __wt_hazard_empty(WT_SESSION_IMPL *session, const char *name);
+void __wt_hazard_validate(WT_SESSION_IMPL *session, WT_PAGE *page);
+int __wt_huffman_open(WT_SESSION_IMPL *session,
     void *symbol_frequency_array,
     u_int symcnt,
     u_int numbytes,
     void *retp);
-void __wt_huffman_close(SESSION *session, void *huffman_arg);
+void __wt_huffman_close(WT_SESSION_IMPL *session, void *huffman_arg);
 int __wt_print_huffman_code(void *huffman_arg, uint16_t symbol);
-int __wt_huffman_encode(SESSION *session,
+int __wt_huffman_encode(WT_SESSION_IMPL *session,
     void *huffman_arg,
     const uint8_t *from_arg,
     uint32_t from_len,
     WT_BUF *to_buf);
-int __wt_huffman_decode(SESSION *session,
+int __wt_huffman_decode(WT_SESSION_IMPL *session,
     void *huffman_arg,
     const uint8_t *from_arg,
     uint32_t from_len,
@@ -361,47 +386,53 @@ int __wt_huffman_decode(SESSION *session,
 uint32_t __wt_nlpo2_round(uint32_t v);
 uint32_t __wt_nlpo2(uint32_t v);
 int __wt_ispo2(uint32_t v);
-int __wt_buf_init(SESSION *session, WT_BUF *buf, size_t size);
-int __wt_buf_initsize(SESSION *session, WT_BUF *buf, size_t size);
-int __wt_buf_grow(SESSION *session, WT_BUF *buf, size_t size);
-int __wt_buf_set(SESSION *session,
+int __wt_buf_init(WT_SESSION_IMPL *session, WT_BUF *buf, size_t size);
+int __wt_buf_initsize(WT_SESSION_IMPL *session, WT_BUF *buf, size_t size);
+int __wt_buf_grow(WT_SESSION_IMPL *session, WT_BUF *buf, size_t size);
+int __wt_buf_set( WT_SESSION_IMPL *session,
     WT_BUF *buf,
     const void *data,
     uint32_t size);
-void __wt_buf_steal( SESSION *session,
+void __wt_buf_steal( WT_SESSION_IMPL *session,
     WT_BUF *buf,
     const void *datap,
     uint32_t *sizep);
-void __wt_buf_free(SESSION *session, WT_BUF *buf);
-int __wt_scr_alloc(SESSION *session, uint32_t size, WT_BUF **scratchp);
+void __wt_buf_free(WT_SESSION_IMPL *session, WT_BUF *buf);
+int __wt_scr_alloc(WT_SESSION_IMPL *session, uint32_t size, WT_BUF **scratchp);
 void __wt_scr_release(WT_BUF **bufp);
-void __wt_scr_free(SESSION *session);
-int __wt_session_serialize_func(SESSION *session,
+void __wt_scr_free(WT_SESSION_IMPL *session);
+int __wt_session_serialize_func(WT_SESSION_IMPL *session,
     wq_state_t op,
     int spin,
-    int (*func)(SESSION *),
+    int (*func)(WT_SESSION_IMPL *),
     void *args);
-void __wt_session_serialize_wrapup(SESSION *session, WT_PAGE *page, int ret);
-int __wt_sb_alloc(SESSION *session,
+void __wt_session_serialize_wrapup(WT_SESSION_IMPL *session,
+    WT_PAGE *page,
+    int ret);
+int __wt_sb_alloc( WT_SESSION_IMPL *session,
     size_t size,
     void *retp,
-    SESSION_BUFFER **sbp);
-void __wt_sb_free(SESSION *session, SESSION_BUFFER *sb);
-void __wt_sb_decrement(SESSION *session, SESSION_BUFFER *sb);
-int __wt_stat_alloc_btree_stats(SESSION *session, WT_BTREE_STATS **statsp);
+    WT_SESSION_BUFFER **sbp);
+void __wt_sb_free(WT_SESSION_IMPL *session, WT_SESSION_BUFFER *sb);
+void __wt_sb_decrement(WT_SESSION_IMPL *session, WT_SESSION_BUFFER *sb);
+int __wt_stat_alloc_btree_stats(WT_SESSION_IMPL *session,
+    WT_BTREE_STATS **statsp);
 void __wt_stat_clear_btree_stats(WT_BTREE_STATS *stats);
 void __wt_stat_print_btree_stats(WT_BTREE_STATS *stats, FILE *stream);
-int __wt_stat_alloc_btree_file_stats(SESSION *session,
+int __wt_stat_alloc_btree_file_stats(WT_SESSION_IMPL *session,
     WT_BTREE_FILE_STATS **statsp);
 void __wt_stat_clear_btree_file_stats(WT_BTREE_FILE_STATS *stats);
 void __wt_stat_print_btree_file_stats(WT_BTREE_FILE_STATS *stats, FILE *stream);
-int __wt_stat_alloc_cache_stats(SESSION *session, WT_CACHE_STATS **statsp);
+int __wt_stat_alloc_cache_stats(WT_SESSION_IMPL *session,
+    WT_CACHE_STATS **statsp);
 void __wt_stat_clear_cache_stats(WT_CACHE_STATS *stats);
 void __wt_stat_print_cache_stats(WT_CACHE_STATS *stats, FILE *stream);
-int __wt_stat_alloc_conn_stats(SESSION *session, WT_CONN_STATS **statsp);
+int __wt_stat_alloc_conn_stats(WT_SESSION_IMPL *session,
+    WT_CONN_STATS **statsp);
 void __wt_stat_clear_conn_stats(WT_CONN_STATS *stats);
 void __wt_stat_print_conn_stats(WT_CONN_STATS *stats, FILE *stream);
-int __wt_stat_alloc_file_stats(SESSION *session, WT_FILE_STATS **statsp);
+int __wt_stat_alloc_file_stats(WT_SESSION_IMPL *session,
+    WT_FILE_STATS **statsp);
 void __wt_stat_clear_file_stats(WT_FILE_STATS *stats);
 void __wt_stat_print_file_stats(WT_FILE_STATS *stats, FILE *stream);
 
diff --git a/src/include/intpack.i b/src/include/intpack.i
index e0685f72924..fa2ba304c3e 100644
--- a/src/include/intpack.i
+++ b/src/include/intpack.i
@@ -49,7 +49,8 @@
  *      Packs a positive variable-length integer in the specified location.
  */
 static inline int
-__wt_pack_posint(SESSION *session, uint8_t **pp, size_t maxlen, uint64_t x)
+__wt_pack_posint(
+    WT_SESSION_IMPL *session, uint8_t **pp, size_t maxlen, uint64_t x)
 {
 	uint8_t *p;
 	int len, shift;
@@ -76,7 +77,8 @@ __wt_pack_posint(SESSION *session, uint8_t **pp, size_t maxlen, uint64_t x)
  *      Packs a negative variable-length integer in the specified location.
  */
 static inline int
-__wt_pack_negint(SESSION *session, uint8_t **pp, size_t maxlen, uint64_t x)
+__wt_pack_negint(
+    WT_SESSION_IMPL *session, uint8_t **pp, size_t maxlen, uint64_t x)
 {
 	uint8_t *p;
 	int len, shift;
@@ -108,7 +110,7 @@ __wt_pack_negint(SESSION *session, uint8_t **pp, size_t maxlen, uint64_t x)
  */
 static inline int
 __wt_unpack_posint(
-    SESSION *session, uint8_t **pp, size_t maxlen, uint64_t *retp)
+    WT_SESSION_IMPL *session, uint8_t **pp, size_t maxlen, uint64_t *retp)
 {
 	uint64_t x;
 	uint8_t *p;
@@ -134,7 +136,7 @@ __wt_unpack_posint(
  */
 static inline int
 __wt_unpack_negint(
-    SESSION *session, uint8_t **pp, size_t maxlen, uint64_t *retp)
+    WT_SESSION_IMPL *session, uint8_t **pp, size_t maxlen, uint64_t *retp)
 {
 	uint64_t x;
 	uint8_t *p;
@@ -159,7 +161,8 @@ __wt_unpack_negint(
  *      Variable-sized packing for unsigned integers
  */
 static inline int
-__wt_vpack_uint(SESSION *session, uint8_t **pp, size_t maxlen, uint64_t x)
+__wt_vpack_uint(
+    WT_SESSION_IMPL *session, uint8_t **pp, size_t maxlen, uint64_t x)
 {
 	uint8_t *p;
 
@@ -186,7 +189,7 @@ __wt_vpack_uint(SESSION *session, uint8_t **pp, size_t maxlen, uint64_t x)
  *      Variable-sized packing for signed integers
  */
 static inline int
-__wt_vpack_int(SESSION *session, uint8_t **pp, size_t maxlen, int64_t x)
+__wt_vpack_int(WT_SESSION_IMPL *session, uint8_t **pp, size_t maxlen, int64_t x)
 {
 	uint8_t *p;
 
@@ -215,7 +218,8 @@ __wt_vpack_int(SESSION *session, uint8_t **pp, size_t maxlen, int64_t x)
  *      Variable-sized unpacking for unsigned integers
  */
 static inline int
-__wt_vunpack_uint(SESSION *session, uint8_t **pp, size_t maxlen, uint64_t *xp)
+__wt_vunpack_uint(
+    WT_SESSION_IMPL *session, uint8_t **pp, size_t maxlen, uint64_t *xp)
 {
 	uint8_t *p;
 
@@ -251,7 +255,8 @@ __wt_vunpack_uint(SESSION *session, uint8_t **pp, size_t maxlen, uint64_t *xp)
  *      Variable-sized packing for signed integers
  */
 static inline int
-__wt_vunpack_int(SESSION *session, uint8_t **pp, size_t maxlen, int64_t *xp)
+__wt_vunpack_int(
+    WT_SESSION_IMPL *session, uint8_t **pp, size_t maxlen, int64_t *xp)
 {
 	uint8_t *p;
 
diff --git a/src/include/log.i b/src/include/log.i
index eabdeff10f6..9ac5e04e9de 100644
--- a/src/include/log.i
+++ b/src/include/log.i
@@ -1,7 +1,7 @@
 /* DO NOT EDIT: automatically built by dist/log.py. */
 
 static inline int
-__wt_logput_debug(SESSION *session, const char * message)
+__wt_logput_debug(WT_SESSION_IMPL *session, const char * message)
 {
 	return (__wt_log_put(session, &__wt_logdesc_debug, message));
 }
diff --git a/src/include/misc.h b/src/include/misc.h
index 0b36afb55f0..996b1bb0f82 100644
--- a/src/include/misc.h
+++ b/src/include/misc.h
@@ -28,13 +28,13 @@ extern "C" {
 
 /*
  * XXX
- * The server threads use their own SESSION handles because they may want to
- * block (for example, the eviction server calls reconciliation, and some of
- * the reconciliation diagnostic code reads pages), and the user's session
- * handle is already blocking on a server thread.  The problem is the server
- * thread needs to reference the correct btree handle, and that's hanging off
- * the application's thread of control.  For now, I'm just making it obvious
- * where that's getting done.
+ * The server threads use their own WT_SESSION_IMPL handles because they may
+ * want to block (for example, the eviction server calls reconciliation, and
+ * some of the reconciliation diagnostic code reads pages), and the user's
+ * session handle is already blocking on a server thread.  The problem is the
+ * server thread needs to reference the correct btree handle, and that's
+ * hanging off the application's thread of control.  For now, I'm just making
+ * it obvious where that's getting done.
  */
 #define	WT_SET_BTREE_IN_SESSION(s, b)					\
 	((s)->btree = (b))
diff --git a/src/include/progress.i b/src/include/progress.i
index 4111357ddcc..d6969a1b073 100644
--- a/src/include/progress.i
+++ b/src/include/progress.i
@@ -10,7 +10,7 @@
  *	Send a progress message to stdout.
  */
 static inline void
-__wt_progress(SESSION *session, const char *s, uint64_t v)
+__wt_progress(WT_SESSION_IMPL *session, const char *s, uint64_t v)
 {
 	WT_EVENT_HANDLER *handler;
 
diff --git a/src/include/verify_build.h b/src/include/verify_build.h
index d105cbc514f..8c0f78066de 100644
--- a/src/include/verify_build.h
+++ b/src/include/verify_build.h
@@ -65,7 +65,7 @@ __wt_verify_build(void)
 	/* There are also structures that must be aligned correctly. */
 	ALIGN_CHECK(WT_OFF, sizeof(uint32_t));
 	ALIGN_CHECK(WT_PAGE_DISK, sizeof(uint32_t));
-	ALIGN_CHECK(SESSION_BUFFER, sizeof(uint32_t));
+	ALIGN_CHECK(WT_SESSION_BUFFER, sizeof(uint32_t));
 
 	/*
 	 * We mix-and-match 32-bit unsigned values and size_t's, mostly because
diff --git a/src/include/wt_internal.in b/src/include/wt_internal.in
index b12597bdeeb..eec87cf9ded 100644
--- a/src/include/wt_internal.in
+++ b/src/include/wt_internal.in
@@ -45,20 +45,14 @@ extern "C" {
  * DO NOT EDIT: automatically built by dist/s_typedef.
  * Forward structure declarations for internal structures: BEGIN
  */
-struct __btree;
-    typedef struct __btree BTREE;
-struct __btree_session;
-    typedef struct __btree_session BTREE_SESSION;
-struct __connection;
-    typedef struct __connection CONNECTION;
-struct __session;
-    typedef struct __session SESSION;
-struct __session_buffer;
-    typedef struct __session_buffer SESSION_BUFFER;
+struct __wt_btree;
+    typedef struct __wt_btree WT_BTREE;
 struct __wt_btree_desc;
     typedef struct __wt_btree_desc WT_BTREE_DESC;
 struct __wt_btree_file_stats;
     typedef struct __wt_btree_file_stats WT_BTREE_FILE_STATS;
+struct __wt_btree_session;
+    typedef struct __wt_btree_session WT_BTREE_SESSION;
 struct __wt_btree_stats;
     typedef struct __wt_btree_stats WT_BTREE_STATS;
 struct __wt_cache;
@@ -73,6 +67,8 @@ struct __wt_col_ref;
     typedef struct __wt_col_ref WT_COL_REF;
 struct __wt_conn_stats;
     typedef struct __wt_conn_stats WT_CONN_STATS;
+struct __wt_connection_impl;
+    typedef struct __wt_connection_impl WT_CONNECTION_IMPL;
 struct __wt_dlh;
     typedef struct __wt_dlh WT_DLH;
 struct __wt_evict_list;
@@ -107,6 +103,10 @@ struct __wt_row;
     typedef struct __wt_row WT_ROW;
 struct __wt_row_ref;
     typedef struct __wt_row_ref WT_ROW_REF;
+struct __wt_session_buffer;
+    typedef struct __wt_session_buffer WT_SESSION_BUFFER;
+struct __wt_session_impl;
+    typedef struct __wt_session_impl WT_SESSION_IMPL;
 struct __wt_stats;
     typedef struct __wt_stats WT_STATS;
 struct __wt_update;
@@ -139,15 +139,15 @@ struct __wt_walk_entry;
 #include "stat.h"
 
 /*******************************************
- * SESSION support.
+ * WT_SESSION_IMPL support.
  *******************************************/
-#define	S2C(session) ((CONNECTION *)(session)->iface.connection)
+#define	S2C(session) ((WT_CONNECTION_IMPL *)(session)->iface.connection)
 
 /*
- * SESSION_BUFFER --
+ * WT_SESSION_BUFFER --
  *	A structure to accumulate file changes on a per-thread basis.
  */
-struct __session_buffer {
+struct __wt_session_buffer {
 	uint32_t len;				/* Buffer original size */
 	uint32_t space_avail;			/* Buffer's available memory */
 	uint8_t *first_free;			/* Buffer's first free byte */
diff --git a/src/log/log.c b/src/log/log.c
index 2b0961994dc..b94e120a3cd 100644
--- a/src/log/log.c
+++ b/src/log/log.c
@@ -8,7 +8,7 @@
 #include "wt_internal.h"
 
 static int
-__log_record_size(SESSION *session,
+__log_record_size(WT_SESSION_IMPL *session,
     WT_LOGREC_DESC *recdesc, va_list ap, size_t *sizep)
 {
 	WT_UNUSED(session);
@@ -18,7 +18,7 @@ __log_record_size(SESSION *session,
 }
 
 int
-__wt_log_put(SESSION *session, WT_LOGREC_DESC *recdesc, ...)
+__wt_log_put(WT_SESSION_IMPL *session, WT_LOGREC_DESC *recdesc, ...)
 {
 	WT_BUF *buf;
 	va_list ap;
@@ -41,9 +41,9 @@ err:	va_end(ap);
 }
 
 int
-__wt_log_vprintf(SESSION *session, const char *fmt, va_list ap)
+__wt_log_vprintf(WT_SESSION_IMPL *session, const char *fmt, va_list ap)
 {
-	CONNECTION *conn;
+	WT_CONNECTION_IMPL *conn;
 	WT_BUF *buf;
 	va_list ap_copy;
 	size_t len;
@@ -77,7 +77,7 @@ __wt_log_vprintf(SESSION *session, const char *fmt, va_list ap)
 }
 
 int
-__wt_log_printf(SESSION *session, const char *fmt, ...)
+__wt_log_printf(WT_SESSION_IMPL *session, const char *fmt, ...)
     WT_GCC_ATTRIBUTE ((format (printf, 2, 3)))
 {
 	va_list ap;
diff --git a/src/os_posix/os_abort.c b/src/os_posix/os_abort.c
index 3fcf7ebc287..318316e185f 100644
--- a/src/os_posix/os_abort.c
+++ b/src/os_posix/os_abort.c
@@ -12,7 +12,7 @@
  *	Abort the process, dropping core.
  */
 void
-__wt_abort(SESSION *session)
+__wt_abort(WT_SESSION_IMPL *session)
 {
 	__wt_msg(session, "aborting WiredTiger library");
 
diff --git a/src/os_posix/os_alloc.c b/src/os_posix/os_alloc.c
index 272a2b701b1..e2f2cc4cc5c 100644
--- a/src/os_posix/os_alloc.c
+++ b/src/os_posix/os_alloc.c
@@ -21,13 +21,13 @@
  *	ANSI calloc function.
  */
 int
-__wt_calloc(SESSION *session, size_t number, size_t size, void *retp)
+__wt_calloc(WT_SESSION_IMPL *session, size_t number, size_t size, void *retp)
 {
 	void *p;
 
 	/*
 	 * !!!
-	 * This function MUST handle a NULL SESSION handle.
+	 * This function MUST handle a NULL WT_SESSION_IMPL handle.
 	 */
 	WT_ASSERT(session, number != 0 && size != 0);
 
@@ -48,7 +48,7 @@ __wt_calloc(SESSION *session, size_t number, size_t size, void *retp)
  *	ANSI realloc function.
  */
 int
-__wt_realloc(SESSION *session,
+__wt_realloc(WT_SESSION_IMPL *session,
     uint32_t *bytes_allocated_ret, size_t bytes_to_allocate, void *retp)
 {
 	void *p;
@@ -56,7 +56,7 @@ __wt_realloc(SESSION *session,
 
 	/*
 	 * !!!
-	 * This function MUST handle a NULL SESSION handle.
+	 * This function MUST handle a NULL WT_SESSION_IMPL handle.
 	 */
 	WT_ASSERT(session, bytes_to_allocate != 0);
 
@@ -105,7 +105,7 @@ __wt_realloc(SESSION *session,
  *	ANSI strdup function.
  */
 int
-__wt_strdup(SESSION *session, const char *str, void *retp)
+__wt_strdup(WT_SESSION_IMPL *session, const char *str, void *retp)
 {
 	size_t len;
 	void *p;
@@ -117,7 +117,7 @@ __wt_strdup(SESSION *session, const char *str, void *retp)
 
 	/*
 	 * !!!
-	 * This function MUST handle a NULL SESSION handle.
+	 * This function MUST handle a NULL WT_SESSION_IMPL handle.
 	 */
 	if (session != NULL && S2C(session)->stats != NULL)
 		WT_STAT_INCR(S2C(session)->stats, memalloc);
@@ -135,13 +135,13 @@ __wt_strdup(SESSION *session, const char *str, void *retp)
  *	ANSI free function.
  */
 void
-__wt_free_int(SESSION *session, void *p_arg)
+__wt_free_int(WT_SESSION_IMPL *session, void *p_arg)
 {
 	void *p;
 
 	/*
 	 * !!!
-	 * This function MUST handle a NULL SESSION handle.
+	 * This function MUST handle a NULL WT_SESSION_IMPL handle.
 	 */
 	if (session != NULL && S2C(session)->stats != NULL)
 		WT_STAT_INCR(S2C(session)->stats, memfree);
diff --git a/src/os_posix/os_dlopen.c b/src/os_posix/os_dlopen.c
index 17e63754b8c..5b88eb2ba27 100644
--- a/src/os_posix/os_dlopen.c
+++ b/src/os_posix/os_dlopen.c
@@ -12,9 +12,9 @@
  *	Open a dynamic library.
  */
 int
-__wt_dlopen(SESSION *session, const char *path, WT_DLH **dlhp)
+__wt_dlopen(WT_SESSION_IMPL *session, const char *path, WT_DLH **dlhp)
 {
-	CONNECTION *conn;
+	WT_CONNECTION_IMPL *conn;
 	WT_DLH *dlh;
 	int ret;
 
@@ -50,7 +50,8 @@ err:		__wt_free(session, dlh->name);
  *	Lookup a symbol in a dynamic library.
  */
 int
-__wt_dlsym(SESSION *session, WT_DLH *dlh, const char *name, void **sym_ret)
+__wt_dlsym(WT_SESSION_IMPL *session,
+    WT_DLH *dlh, const char *name, void **sym_ret)
 {
 	void *sym;
 
@@ -69,9 +70,9 @@ __wt_dlsym(SESSION *session, WT_DLH *dlh, const char *name, void **sym_ret)
  *	Close a dynamic library
  */
 int
-__wt_dlclose(SESSION *session, WT_DLH *dlh)
+__wt_dlclose(WT_SESSION_IMPL *session, WT_DLH *dlh)
 {
-	CONNECTION *conn;
+	WT_CONNECTION_IMPL *conn;
 	int ret;
 
 	conn = S2C(session);
diff --git a/src/os_posix/os_filesize.c b/src/os_posix/os_filesize.c
index ed7143ad398..9a247be5fb4 100644
--- a/src/os_posix/os_filesize.c
+++ b/src/os_posix/os_filesize.c
@@ -12,7 +12,7 @@
  *	Get the size of a file in bytes.
  */
 int
-__wt_filesize(SESSION *session, WT_FH *fh, off_t *sizep)
+__wt_filesize(WT_SESSION_IMPL *session, WT_FH *fh, off_t *sizep)
 {
 	struct stat sb;
 
diff --git a/src/os_posix/os_fsync.c b/src/os_posix/os_fsync.c
index 33e69563099..49df369cd0e 100644
--- a/src/os_posix/os_fsync.c
+++ b/src/os_posix/os_fsync.c
@@ -12,7 +12,7 @@
  *	Flush a file handle.
  */
 int
-__wt_fsync(SESSION *session, WT_FH *fh)
+__wt_fsync(WT_SESSION_IMPL *session, WT_FH *fh)
 {
 
 	WT_STAT_INCR(fh->stats, fsync);
diff --git a/src/os_posix/os_ftruncate.c b/src/os_posix/os_ftruncate.c
index e1e9fdf7691..a69956ec710 100644
--- a/src/os_posix/os_ftruncate.c
+++ b/src/os_posix/os_ftruncate.c
@@ -12,7 +12,7 @@
  *	Truncate a file.
  */
 int
-__wt_ftruncate(SESSION *session, WT_FH *fh, off_t len)
+__wt_ftruncate(WT_SESSION_IMPL *session, WT_FH *fh, off_t len)
 {
 	if (ftruncate(fh->fd, len) == 0) {
 		fh->file_size = len;
diff --git a/src/os_posix/os_mtx.c b/src/os_posix/os_mtx.c
index 178ae77f725..0a0f4fcba23 100644
--- a/src/os_posix/os_mtx.c
+++ b/src/os_posix/os_mtx.c
@@ -12,7 +12,8 @@
  *	Allocate and initialize a pthread mutex.
  */
 int
-__wt_mtx_alloc(SESSION *session, const char *name, int is_locked, WT_MTX **mtxp)
+__wt_mtx_alloc(WT_SESSION_IMPL *session,
+    const char *name, int is_locked, WT_MTX **mtxp)
 {
 	WT_MTX *mtx;
 	pthread_condattr_t condattr;
@@ -22,7 +23,7 @@ __wt_mtx_alloc(SESSION *session, const char *name, int is_locked, WT_MTX **mtxp)
 
 	/*
 	 * !!!
-	 * This function MUST handle a NULL SESSION structure reference.
+	 * This function MUST handle a NULL WT_SESSION_IMPL structure reference.
 	 *
 	 * Initialize the mutex.
 	 * Mutexes are shared between processes.
@@ -68,7 +69,7 @@ err:	__wt_free(session, mtx);
  *	Lock a mutex.
  */
 void
-__wt_lock(SESSION *session, WT_MTX *mtx)
+__wt_lock(WT_SESSION_IMPL *session, WT_MTX *mtx)
 {
 	int ret;
 
@@ -109,7 +110,7 @@ err:	__wt_err(session, ret, "mutex lock failed");
  *	Release a mutex.
  */
 void
-__wt_unlock(SESSION *session, WT_MTX *mtx)
+__wt_unlock(WT_SESSION_IMPL *session, WT_MTX *mtx)
 {
 	int ret;
 
@@ -133,7 +134,7 @@ err:	__wt_err(session, ret, "mutex unlock failed");
  *	Destroy a mutex.
  */
 int
-__wt_mtx_destroy(SESSION *session, WT_MTX *mtx)
+__wt_mtx_destroy(WT_SESSION_IMPL *session, WT_MTX *mtx)
 {
 	int ret;
 
diff --git a/src/os_posix/os_open.c b/src/os_posix/os_open.c
index df014dd6a9b..d6bc39b6eb7 100644
--- a/src/os_posix/os_open.c
+++ b/src/os_posix/os_open.c
@@ -12,11 +12,11 @@
  *	Open a file handle.
  */
 int
-__wt_open(
-    SESSION *session, const char *name, mode_t mode, int ok_create, WT_FH **fhp)
+__wt_open(WT_SESSION_IMPL *session,
+    const char *name, mode_t mode, int ok_create, WT_FH **fhp)
 {
-	BTREE *btree;
-	CONNECTION *conn;
+	WT_BTREE *btree;
+	WT_CONNECTION_IMPL *conn;
 	WT_FH *fh;
 	int f, fd, matched, ret;
 
@@ -102,9 +102,9 @@ err:	if (fh != NULL) {
  *	Close a file handle.
  */
 int
-__wt_close(SESSION *session, WT_FH *fh)
+__wt_close(WT_SESSION_IMPL *session, WT_FH *fh)
 {
-	CONNECTION *conn;
+	WT_CONNECTION_IMPL *conn;
 	int ret;
 
 	conn = S2C(session);
diff --git a/src/os_posix/os_rw.c b/src/os_posix/os_rw.c
index 6a15330a30b..bdfb830891e 100644
--- a/src/os_posix/os_rw.c
+++ b/src/os_posix/os_rw.c
@@ -12,7 +12,8 @@
  *	Read a chunk.
  */
 int
-__wt_read(SESSION *session, WT_FH *fh, off_t offset, uint32_t bytes, void *buf)
+__wt_read(WT_SESSION_IMPL *session,
+    WT_FH *fh, off_t offset, uint32_t bytes, void *buf)
 {
 	WT_STAT_INCR(fh->stats, read_io);
 	WT_STAT_INCR(S2C(session)->stats, total_read_io);
@@ -35,7 +36,8 @@ __wt_read(SESSION *session, WT_FH *fh, off_t offset, uint32_t bytes, void *buf)
  *	Write a chunk.
  */
 int
-__wt_write(SESSION *session, WT_FH *fh, off_t offset, uint32_t bytes, void *buf)
+__wt_write(WT_SESSION_IMPL *session,
+    WT_FH *fh, off_t offset, uint32_t bytes, void *buf)
 {
 	WT_STAT_INCR(fh->stats, write_io);
 	WT_STAT_INCR(S2C(session)->stats, total_write_io);
diff --git a/src/support/cksum.c b/src/support/cksum.c
index bdd1034264f..1fc08968d5d 100644
--- a/src/support/cksum.c
+++ b/src/support/cksum.c
@@ -21,7 +21,7 @@
  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
- * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * ARISING FROM, OUT OF OR IN WT_CONNECTION_IMPL WITH THE SOFTWARE OR THE USE OR
  * OTHER DEALINGS IN THE SOFTWARE.
  */
 
diff --git a/src/support/err.c b/src/support/err.c
index 0427122403b..9e4b8677cb7 100644
--- a/src/support/err.c
+++ b/src/support/err.c
@@ -12,7 +12,7 @@
  * 	Report an error (va_list version).
  */
 void
-__wt_errv(SESSION *session, int error,
+__wt_errv(WT_SESSION_IMPL *session, int error,
     const char *prefix1, const char *prefix2, const char *fmt, va_list ap)
 {
 	WT_EVENT_HANDLER *handler;
@@ -50,7 +50,7 @@ __wt_errv(SESSION *session, int error,
  * 	Report an error.
  */
 void
-__wt_err(SESSION *session, int error, const char *fmt, ...)
+__wt_err(WT_SESSION_IMPL *session, int error, const char *fmt, ...)
     WT_GCC_ATTRIBUTE ((format (printf, 3, 4)))
 {
 	va_list ap;
@@ -68,7 +68,7 @@ __wt_err(SESSION *session, int error, const char *fmt, ...)
  * 	Report an error with no error code.
  */
 void
-__wt_errx(SESSION *session, const char *fmt, ...)
+__wt_errx(WT_SESSION_IMPL *session, const char *fmt, ...)
     WT_GCC_ATTRIBUTE ((format (printf, 2, 3)))
 {
 	va_list ap;
@@ -86,7 +86,7 @@ __wt_errx(SESSION *session, const char *fmt, ...)
  *	Pass a message to a callback function.
  */
 void
-__wt_msgv(SESSION *session, const char *prefix1, const char *prefix2,
+__wt_msgv(WT_SESSION_IMPL *session, const char *prefix1, const char *prefix2,
     const char *fmt, va_list ap)
 {
 	WT_EVENT_HANDLER *handler;
@@ -120,7 +120,7 @@ __wt_msgv(SESSION *session, const char *prefix1, const char *prefix2,
  * 	Report a message.
  */
 void
-__wt_msg(SESSION *session, const char *fmt, ...)
+__wt_msg(WT_SESSION_IMPL *session, const char *fmt, ...)
     WT_GCC_ATTRIBUTE ((format (printf, 2, 3)))
 {
 	va_list ap;
@@ -139,7 +139,8 @@ __wt_msg(SESSION *session, const char *fmt, ...)
  */
 void
 __wt_assert(
-    SESSION *session, const char *check, const char *file_name, int line_number)
+    WT_SESSION_IMPL *session, const char *check,
+    const char *file_name, int line_number)
 {
 	__wt_errx(session,
 	    "assertion failure: %s/%d: \"%s\"", file_name, line_number, check);
@@ -155,7 +156,7 @@ __wt_assert(
  *	discovered.
  */
 int
-__wt_file_format(SESSION *session)
+__wt_file_format(WT_SESSION_IMPL *session)
 {
 	__wt_errx(session, "the file is corrupted; use the Db.salvage"
 	    " method or the db_salvage utility to repair the file");
@@ -168,7 +169,7 @@ __wt_file_format(SESSION *session)
  *	Print a standard error message when an element is too large to store.
  */
 int
-__wt_file_item_too_big(SESSION *session)
+__wt_file_item_too_big(WT_SESSION_IMPL *session)
 {
 	__wt_errx(session, "the item is too large for the file to store");
 	return (WT_ERROR);
diff --git a/src/support/hazard.c b/src/support/hazard.c
index 47d9d342730..6648c27cd3e 100644
--- a/src/support/hazard.c
+++ b/src/support/hazard.c
@@ -12,13 +12,13 @@
  *	Set a hazard reference.
  */
 int
-__wt_hazard_set(SESSION *session, WT_REF *ref
+__wt_hazard_set(WT_SESSION_IMPL *session, WT_REF *ref
 #ifdef HAVE_DIAGNOSTIC
     , const char *file, int line
 #endif
     )
 {
-	CONNECTION *conn;
+	WT_CONNECTION_IMPL *conn;
 	WT_HAZARD *hp;
 
 	conn = S2C(session);
@@ -30,7 +30,7 @@ __wt_hazard_set(SESSION *session, WT_REF *ref
 	 * of WT_REF_MEM, which can be set to WT_REF_LOCKED at any time by the
 	 * page eviction server.
 	 *
-	 * Add the WT_REF reference to the SESSION's hazard list and flush the
+	 * Add the WT_REF reference to the session's hazard list and flush the
 	 * write, then see if the state field is still WT_REF_MEM.  If it's
 	 * still WT_REF_MEM, we can use the page because the page eviction
 	 * server will see our hazard reference before it discards the buffer
@@ -79,7 +79,8 @@ __wt_hazard_set(SESSION *session, WT_REF *ref
 		return (0);
 	}
 
-	__wt_errx(session, "SESSION has no more hazard reference slots");
+	__wt_errx(session,
+            "There are no more hazard reference slots in the session");
 	WT_ASSERT(session, hp < session->hazard + conn->hazard_size);
 	return (0);
 }
@@ -89,9 +90,9 @@ __wt_hazard_set(SESSION *session, WT_REF *ref
  *	Clear a hazard reference.
  */
 void
-__wt_hazard_clear(SESSION *session, WT_PAGE *page)
+__wt_hazard_clear(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
-	CONNECTION *conn;
+	WT_CONNECTION_IMPL *conn;
 	WT_HAZARD *hp;
 
 	conn = S2C(session);
@@ -119,7 +120,7 @@ __wt_hazard_clear(SESSION *session, WT_PAGE *page)
 			 */
 			return;
 		}
-	__wt_errx(session, "SESSION hazard reference not found");
+	__wt_errx(session, "WT_SESSION_IMPL hazard reference not found");
 	WT_ASSERT(session, hp < session->hazard + conn->hazard_size);
 }
 
@@ -128,22 +129,22 @@ __wt_hazard_clear(SESSION *session, WT_PAGE *page)
  *	Verify that no hazard references are set.
  */
 void
-__wt_hazard_empty(SESSION *session, const char *name)
+__wt_hazard_empty(WT_SESSION_IMPL *session, const char *name)
 {
-	CONNECTION *conn;
+	WT_CONNECTION_IMPL *conn;
 	WT_HAZARD *hp;
 
 	conn = S2C(session);
 
 	/*
-	 * Check for a set hazard reference and complain if we find one.  Clear
-	 * any we find because it's not a correctness problem (any hazard ref
-	 * we find can't be real because the SESSION is being closed when we're
-	 * called).   We do this work because it's not expensive, and we don't
-	 * want to let a hazard reference lie around, keeping a page from being
-	 * flushed.  The flush isn't necessary for correctness, but gives the
-	 * cache eviction thread immediate access to any page our reference
-	 * blocks.
+         * Check for a set hazard reference and complain if we find one.  Clear
+         * any we find because it's not a correctness problem (any hazard ref
+         * we find can't be real because the session is being closed when we're
+         * called).   We do this work because it's not expensive, and we don't
+         * want to let a hazard reference lie around, keeping a page from being
+         * flushed.  The flush isn't necessary for correctness, but gives the
+         * cache eviction thread immediate access to any page our reference
+         * blocks.
 	 */
 	for (hp = session->hazard;
 	    hp < session->hazard + conn->hazard_size; ++hp)
@@ -167,11 +168,11 @@ __wt_hazard_empty(SESSION *session, const char *name)
  *	Confirm that a page isn't on the hazard list.
  */
 void
-__wt_hazard_validate(SESSION *session, WT_PAGE *page)
+__wt_hazard_validate(WT_SESSION_IMPL *session, WT_PAGE *page)
 {
-	CONNECTION *conn;
+	WT_CONNECTION_IMPL *conn;
 	WT_HAZARD *hp;
-	SESSION **tp;
+	WT_SESSION_IMPL **tp;
 
 	conn = S2C(session);
 
diff --git a/src/support/huffman.c b/src/support/huffman.c
index 9678ca11e97..4227b012c50 100644
--- a/src/support/huffman.c
+++ b/src/support/huffman.c
@@ -105,13 +105,15 @@ typedef struct __indexed_byte {
 static int  indexed_freq_compare(const void *, const void *);
 static int  indexed_symbol_compare(const void *, const void *);
 static void make_table(
-	SESSION *, uint16_t *, uint16_t, WT_HUFFMAN_CODE *, u_int);
-static void node_queue_close(SESSION *, NODE_QUEUE *);
-static void node_queue_dequeue(SESSION *, NODE_QUEUE *, WT_FREQTREE_NODE **);
-static int  node_queue_enqueue(SESSION *, NODE_QUEUE *, WT_FREQTREE_NODE *);
+	WT_SESSION_IMPL *, uint16_t *, uint16_t, WT_HUFFMAN_CODE *, u_int);
+static void node_queue_close(WT_SESSION_IMPL *, NODE_QUEUE *);
+static void node_queue_dequeue(
+        WT_SESSION_IMPL *, NODE_QUEUE *, WT_FREQTREE_NODE **);
+static int  node_queue_enqueue(
+        WT_SESSION_IMPL *, NODE_QUEUE *, WT_FREQTREE_NODE *);
 static uint32_t profile_tree(
 	WT_FREQTREE_NODE *, uint16_t, uint16_t *, uint16_t *);
-static void recursive_free_node(SESSION *, WT_FREQTREE_NODE *);
+static void recursive_free_node(WT_SESSION_IMPL *, WT_FREQTREE_NODE *);
 static void set_codes(WT_FREQTREE_NODE *, WT_HUFFMAN_CODE *, uint16_t, uint8_t);
 
 #define	node_queue_is_empty(queue)					\
@@ -239,7 +241,7 @@ set_codes(WT_FREQTREE_NODE *node,
  * decoding from a code to a symbol are simple array lookups.
  */
 static void
-make_table(SESSION *session, uint16_t *code2symbol,
+make_table(WT_SESSION_IMPL *session, uint16_t *code2symbol,
     uint16_t max_depth, WT_HUFFMAN_CODE *codes, u_int symcnt)
 {
 	uint32_t j, c1, c2;	/* Exceeds uint16_t bounds at loop boundary. */
@@ -281,7 +283,7 @@ make_table(SESSION *session, uint16_t *code2symbol,
  *	Recursively free the huffman frequency tree's nodes.
  */
 static void
-recursive_free_node(SESSION *session, WT_FREQTREE_NODE *node)
+recursive_free_node(WT_SESSION_IMPL *session, WT_FREQTREE_NODE *node)
 {
 	if (node != NULL) {
 		recursive_free_node(session, node->left);
@@ -295,7 +297,7 @@ recursive_free_node(SESSION *session, WT_FREQTREE_NODE *node)
  *	Take a frequency table and return a pointer to a descriptor object.
  */
 int
-__wt_huffman_open(SESSION *session,
+__wt_huffman_open(WT_SESSION_IMPL *session,
     void *symbol_frequency_array, u_int symcnt, u_int numbytes, void *retp)
 {
 	INDEXED_SYMBOL *indexed_freqs;
@@ -532,7 +534,7 @@ err:		if (ret == 0)
  *	Discard a Huffman descriptor object.
  */
 void
-__wt_huffman_close(SESSION *session, void *huffman_arg)
+__wt_huffman_close(WT_SESSION_IMPL *session, void *huffman_arg)
 {
 	WT_HUFFMAN_OBJ *huffman;
 
@@ -591,7 +593,7 @@ __wt_print_huffman_code(void *huffman_arg, uint16_t symbol)
  * and write header bits.
  */
 int
-__wt_huffman_encode(SESSION *session, void *huffman_arg,
+__wt_huffman_encode(WT_SESSION_IMPL *session, void *huffman_arg,
     const uint8_t *from_arg, uint32_t from_len, WT_BUF *to_buf)
 {
 	WT_BUF *tmp;
@@ -766,7 +768,7 @@ err:	if (tmp != NULL)
  * Finally, subtract off these bits from the shift register.
  */
 int
-__wt_huffman_decode(SESSION *session, void *huffman_arg,
+__wt_huffman_decode(WT_SESSION_IMPL *session, void *huffman_arg,
     const uint8_t *from_arg, uint32_t from_len, WT_BUF *to_buf)
 {
 	WT_BUF *tmp;
@@ -886,7 +888,7 @@ err:	if (tmp != NULL)
  * It does not delete the pointed huffman tree nodes!
  */
 static void
-node_queue_close(SESSION *session, NODE_QUEUE *queue)
+node_queue_close(WT_SESSION_IMPL *session, NODE_QUEUE *queue)
 {
 	NODE_QUEUE_ELEM *elem, *next_elem;
 
@@ -905,7 +907,8 @@ node_queue_close(SESSION *session, NODE_QUEUE *queue)
  *	Push a tree node to the end of the queue.
  */
 static int
-node_queue_enqueue(SESSION *session, NODE_QUEUE *queue, WT_FREQTREE_NODE *node)
+node_queue_enqueue(
+    WT_SESSION_IMPL *session, NODE_QUEUE *queue, WT_FREQTREE_NODE *node)
 {
 	NODE_QUEUE_ELEM *elem;
 
@@ -939,7 +942,8 @@ node_queue_enqueue(SESSION *session, NODE_QUEUE *queue, WT_FREQTREE_NODE *node)
  *	pointer to the location referred by the retp parameter.
  */
 static void
-node_queue_dequeue(SESSION *session, NODE_QUEUE *queue, WT_FREQTREE_NODE **retp)
+node_queue_dequeue(
+    WT_SESSION_IMPL *session, NODE_QUEUE *queue, WT_FREQTREE_NODE **retp)
 {
 	NODE_QUEUE_ELEM *first_elem;
 
diff --git a/src/support/scratch.c b/src/support/scratch.c
index 18ce3df621b..1a03beb38ff 100644
--- a/src/support/scratch.c
+++ b/src/support/scratch.c
@@ -30,7 +30,7 @@ __wt_buf_clear(WT_BUF *buf)
  *	Initialize a buffer at a specific size.
  */
 int
-__wt_buf_init(SESSION *session, WT_BUF *buf, size_t size)
+__wt_buf_init(WT_SESSION_IMPL *session, WT_BUF *buf, size_t size)
 {
 	WT_ASSERT(session, size <= UINT32_MAX);
 
@@ -48,7 +48,7 @@ __wt_buf_init(SESSION *session, WT_BUF *buf, size_t size)
  *	Initialize a buffer at a specific size, and set the data length.
  */
 int
-__wt_buf_initsize(SESSION *session, WT_BUF *buf, size_t size)
+__wt_buf_initsize(WT_SESSION_IMPL *session, WT_BUF *buf, size_t size)
 {
 	WT_RET(__wt_buf_init(session, buf, size));
 
@@ -62,7 +62,7 @@ __wt_buf_initsize(SESSION *session, WT_BUF *buf, size_t size)
  *	Grow a buffer that's currently in-use.
  */
 int
-__wt_buf_grow(SESSION *session, WT_BUF *buf, size_t size)
+__wt_buf_grow(WT_SESSION_IMPL *session, WT_BUF *buf, size_t size)
 {
 	uint32_t offset;
 
@@ -88,7 +88,8 @@ __wt_buf_grow(SESSION *session, WT_BUF *buf, size_t size)
  *	Set the contents of the buffer.
  */
 int
-__wt_buf_set(SESSION *session, WT_BUF *buf, const void *data, uint32_t size)
+__wt_buf_set(
+    WT_SESSION_IMPL *session, WT_BUF *buf, const void *data, uint32_t size)
 {
 	/* Ensure the buffer is large enough. */
 	WT_RET(__wt_buf_initsize(session, buf, size));
@@ -104,7 +105,7 @@ __wt_buf_set(SESSION *session, WT_BUF *buf, const void *data, uint32_t size)
  */
 void
 __wt_buf_steal(
-    SESSION *session, WT_BUF *buf, const void *datap, uint32_t *sizep)
+    WT_SESSION_IMPL *session, WT_BUF *buf, const void *datap, uint32_t *sizep)
 {
 	/*
 	 * Sometimes we steal a buffer for a different purpose, for example,
@@ -141,7 +142,7 @@ __wt_buf_steal(
  *	Free a buffer.
  */
 void
-__wt_buf_free(SESSION *session, WT_BUF *buf)
+__wt_buf_free(WT_SESSION_IMPL *session, WT_BUF *buf)
 {
 	if (buf->mem != NULL)
 		__wt_free(session, buf->mem);
@@ -153,7 +154,7 @@ __wt_buf_free(SESSION *session, WT_BUF *buf)
  *	Scratch buffer allocation function.
  */
 int
-__wt_scr_alloc(SESSION *session, uint32_t size, WT_BUF **scratchp)
+__wt_scr_alloc(WT_SESSION_IMPL *session, uint32_t size, WT_BUF **scratchp)
 {
 	WT_BUF *buf, **p, *small, **slot;
 	uint32_t allocated;
@@ -164,11 +165,12 @@ __wt_scr_alloc(SESSION *session, uint32_t size, WT_BUF **scratchp)
 	*scratchp = NULL;
 
 	/*
-	 * There's an array of scratch buffers in each SESSION that can be used
-	 * by any function.  We use WT_BUF structures for scratch memory because
-	 * we already have to have functions that do variable-length allocation
-	 * on WT_BUFs.  Scratch buffers are allocated only by a single thread of
-	 * control, so no locking is necessary.
+         * There's an array of scratch buffers in each WT_SESSION_IMPL that can
+         * be used by any function.  We use WT_BUF structures for scratch
+         * memory because we already have to have functions that do
+         * variable-length allocation on WT_BUFs.  Scratch buffers are
+         * allocated only by a single thread of control, so no locking is
+         * necessary.
 	 *
 	 * Walk the array, looking for a buffer we can use.
 	 */
@@ -232,7 +234,7 @@ __wt_scr_alloc(SESSION *session, uint32_t size, WT_BUF **scratchp)
 	return (__wt_scr_alloc(session, size, scratchp));
 
 err:	__wt_errx(session,
-	    "SESSION unable to allocate more scratch buffers");
+	    "WT_SESSION_IMPL unable to allocate more scratch buffers");
 	return (ret);
 }
 
@@ -256,7 +258,7 @@ __wt_scr_release(WT_BUF **bufp)
  *	Free all memory associated with the scratch buffers.
  */
 void
-__wt_scr_free(SESSION *session)
+__wt_scr_free(WT_SESSION_IMPL *session)
 {
 	WT_BUF **p;
 	u_int i;
diff --git a/src/support/serial.c b/src/support/serial.c
index 5ea1f6fd2de..f05d8929d49 100644
--- a/src/support/serial.c
+++ b/src/support/serial.c
@@ -32,16 +32,16 @@
  *	Schedule a serialization request, and block or spin until it completes.
  */
 int
-__wt_session_serialize_func(SESSION *session,
-    wq_state_t op, int spin, int (*func)(SESSION *), void *args)
+__wt_session_serialize_func(WT_SESSION_IMPL *session,
+    wq_state_t op, int spin, int (*func)(WT_SESSION_IMPL *), void *args)
 {
 	int done;
 
 	/*
 	 * Threads serializing access to data using a function:
-	 *	set a function/argument pair in the SESSION handle,
+	 *	set a function/argument pair in the WT_SESSION_IMPL handle,
 	 *	flush memory,
-	 *	update the SESSION workq state, and
+	 *	update the WT_SESSION_IMPL workq state, and
 	 *	spins or blocks.
 	 *
 	 * The workQ thread notices the state change and calls the serialization
@@ -59,9 +59,9 @@ __wt_session_serialize_func(SESSION *session,
 	session->wq_state = op;
 
 	/*
-	 * Callers can spin on the SESSION state (implying the call is quickly
-	 * satisfied), or block until its mutex is unlocked by another thread
-	 * when the operation has completed.
+         * Callers can spin on the session state (implying the call is quickly
+         * satisfied), or block until its mutex is unlocked by another thread
+         * when the operation has completed.
 	 */
 	if (spin) {
 		/*
@@ -94,7 +94,7 @@ __wt_session_serialize_func(SESSION *session,
  *	Server function cleanup.
  */
 void
-__wt_session_serialize_wrapup(SESSION *session, WT_PAGE *page, int ret)
+__wt_session_serialize_wrapup(WT_SESSION_IMPL *session, WT_PAGE *page, int ret)
 {
 	/*
 	 * If passed a page and the return value is good, we modified the page;
diff --git a/src/support/sess_buf.c b/src/support/sess_buf.c
index 403f83e20bf..a2e613aa8df 100644
--- a/src/support/sess_buf.c
+++ b/src/support/sess_buf.c
@@ -9,19 +9,20 @@
 
 /*
  * __wt_sb_alloc --
- *	Allocate memory from the SESSION's buffer and fill it in.
+ *	Allocate memory from the WT_SESSION_IMPL's buffer and fill it in.
  */
 int
-__wt_sb_alloc(SESSION *session, size_t size, void *retp, SESSION_BUFFER **sbp)
+__wt_sb_alloc(
+    WT_SESSION_IMPL *session, size_t size, void *retp, WT_SESSION_BUFFER **sbp)
 {
-	SESSION_BUFFER *sb;
+	WT_SESSION_BUFFER *sb;
 	uint32_t alloc_size, align_size;
 	int single_use;
 
 	/*
-	 * Allocate memory for an insert or change; there's a buffer in the
-	 * SESSION structure for allocation of chunks of memory to hold changed
-	 * or inserted values.
+         * Allocate memory for an insert or change; there's a buffer in the
+         * WT_SESSION_IMPL structure for allocation of chunks of memory to hold
+         * changed or inserted values.
 	 *
 	 * We align allocations because we directly access WT_UPDATE structure
 	 * fields in the memory (the x86 handles unaligned accesses, but I don't
@@ -31,20 +32,21 @@ __wt_sb_alloc(SESSION *session, size_t size, void *retp, SESSION_BUFFER **sbp)
 	 * than with on-disk structures.  Any other code allocating memory from
 	 * this buffer needs to align its allocations as well.
 	 *
-	 * The first thing in each chunk of memory is a SESSION_BUFFER structure
-	 * (which we check is a multiple of 4B during initialization); then one
-	 * or more WT_UPDATE structure plus value chunk pairs.
+         * The first thing in each chunk of memory is a WT_SESSION_BUFFER
+         * structure (which we check is a multiple of 4B during
+         * initialization); then one or more WT_UPDATE structure plus value
+         * chunk pairs.
 	 *
-	 * Figure out how much space we need: this code limits the maximum size
-	 * of a data item stored in the file.  In summary, for a big item we
-	 * have to store a SESSION_BUFFER structure, the WT_UPDATE structure and
-	 * the data, all in an allocated buffer.   We only pass a 32-bit value
-	 * to our allocation routine, so we can't store an item bigger than the
-	 * maximum 32-bit value minus the sizes of those two structures, where
-	 * the WT_UPDATE structure and data item are aligned to a 32-bit
-	 * boundary.  We could fix this, but it's unclear it's worth the effort:
-	 * document you can store a (4GB - 512B) item max, it's insane to store
-	 * 4GB items in the file anyway.
+         * Figure out how much space we need: this code limits the maximum size
+         * of a data item stored in the file.  In summary, for a big item we
+         * have to store a WT_SESSION_BUFFER structure, the WT_UPDATE structure
+         * and the data, all in an allocated buffer.   We only pass a 32-bit
+         * value to our allocation routine, so we can't store an item bigger
+         * than the maximum 32-bit value minus the sizes of those two
+         * structures, where the WT_UPDATE structure and data item are aligned
+         * to a 32-bit boundary.  We could fix this, but it's unclear it's
+         * worth the effort: document you can store a (4GB - 512B) item max,
+         * it's insane to store 4GB items in the file anyway.
 	 */
 	if (size > WT_BTREE_OBJECT_SIZE_MAX)
 		return (__wt_file_item_too_big(session));
@@ -71,7 +73,7 @@ __wt_sb_alloc(SESSION *session, size_t size, void *retp, SESSION_BUFFER **sbp)
 	 * than 4 times the requested size and at least the default buffer size.
 	 */
 	if (align_size > session->update_alloc_size) {
-		alloc_size = WT_SIZEOF32(SESSION_BUFFER) + align_size;
+		alloc_size = WT_SIZEOF32(WT_SESSION_BUFFER) + align_size;
 		single_use = 1;
 	} else {
 		if (session->update_alloc_size < 8 * WT_MEGABYTE)
@@ -84,20 +86,21 @@ __wt_sb_alloc(SESSION *session, size_t size, void *retp, SESSION_BUFFER **sbp)
 	WT_RET(__wt_calloc(session, 1, alloc_size, &sb));
 	WT_ASSERT(session, alloc_size == (uint32_t)alloc_size);
 	sb->len = alloc_size;
-	sb->space_avail = alloc_size - WT_SIZEOF32(SESSION_BUFFER);
-	sb->first_free = (uint8_t *)sb + sizeof(SESSION_BUFFER);
+	sb->space_avail = alloc_size - WT_SIZEOF32(WT_SESSION_BUFFER);
+	sb->first_free = (uint8_t *)sb + sizeof(WT_SESSION_BUFFER);
 
 	/*
-	 * If it's a single use allocation, ignore any current SESSION buffer;
-	 * else, release the old SESSION buffer and replace it with the new one.
+         * If it's a single use allocation, ignore any current buffer in the
+         * session; else, release the old session buffer and replace it with
+         * the new one.
 	 */
 	if (!single_use) {
 		/*
-		 * The "in" reference count is artificially incremented by 1 as
-		 * long as a SESSION buffer is referenced by the SESSION thread;
-		 * we do not want SESSION buffers freed because a page was
-		 * evicted and the count went to 0 while the buffer might still
-		 * be used for future K/V inserts or modifications.
+                 * The "in" reference count is artificially incremented by 1 as
+                 * long as a session buffer is referenced by the session
+                 * handle; we do not want session buffers freed because a page
+                 * was evicted and the count went to 0 while the buffer might
+                 * still be used for future K/V inserts or modifications.
 		 */
 		if (session->sb != NULL)
 			__wt_sb_decrement(session, session->sb);
@@ -120,10 +123,10 @@ no_allocation:
 
 /*
  * __wt_sb_free --
- *	Free a chunk of memory from a per-SESSION buffer.
+ *	Free a chunk of memory from a per-WT_SESSION_IMPL buffer.
  */
 void
-__wt_sb_free(SESSION *session, SESSION_BUFFER *sb)
+__wt_sb_free(WT_SESSION_IMPL *session, WT_SESSION_BUFFER *sb)
 {
 	WT_ASSERT(session, sb->out < sb->in);
 
@@ -133,36 +136,36 @@ __wt_sb_free(SESSION *session, SESSION_BUFFER *sb)
 
 /*
  * __wt_sb_decrement --
- *	Decrement the "insert" value of a per-SESSION buffer.
+ *	Decrement the "insert" value of a per-WT_SESSION_IMPL buffer.
  */
 void
-__wt_sb_decrement(SESSION *session, SESSION_BUFFER *sb)
+__wt_sb_decrement(WT_SESSION_IMPL *session, WT_SESSION_BUFFER *sb)
 {
 	WT_ASSERT(session, sb->out < sb->in);
 
 	/*
 	 * This function is used for two reasons.
 	 *
-	 * #1: it's possible we allocated a WT_UPDATE structure and related K/V
-	 * memory from the SESSION buffer, but then an error occurred.  In this
-	 * case we don't try and clean up the SESSION buffer, it's simpler to
-	 * decrement the counters and pretend the memory is no longer in use.
-	 * We're still in the allocation path, so we decrement the "in" field
-	 * instead of incrementing the "out" field, if the eviction thread were
-	 * to update the "out" field at the same time, we could race.
+         * #1: it's possible we allocated a WT_UPDATE structure and related K/V
+         * memory from the session buffer, but then an error occurred.  In this
+         * case we don't try and clean up the session buffer, it's simpler to
+         * decrement the counters and pretend the memory is no longer in use.
+         * We're still in the allocation path, so we decrement the "in" field
+         * instead of incrementing the "out" field, if the eviction thread were
+         * to update the "out" field at the same time, we could race.
 	 *
-	 * #2: the "in" reference count is artificially incremented by 1 as
-	 * long as a SESSION buffer is referenced by the SESSION thread; we do
-	 * not want SESSION buffers freed because a page was evicted and the
-	 * count went to 0 while the buffer might still be used for future K/V
-	 * inserts or modifications.
+         * #2: the "in" reference count is artificially incremented by 1 as
+         * long as a session buffer is referenced by the session handle; we do
+         * not want session buffers freed because a page was evicted and the
+         * count went to 0 while the buffer might still be used for future K/V
+         * inserts or modifications.
 	 */
 	--sb->in;
 
 	/*
-	 * In the above case #1, if the SESSION buffer was a one-off (allocated
-	 * for a single use), we have to free it here, it's not linked to any
-	 * WT_PAGE in the system.
+         * In the above case #1, if the session buffer was a one-off (allocated
+         * for a single use), we have to free it here, it's not linked to any
+         * WT_PAGE in the system.
 	 *
 	 * In the above case #2, our artificial increment might be the last
 	 * reference, if all of the WT_PAGE's referencing this buffer have been
diff --git a/src/support/stat.c b/src/support/stat.c
index e991a45cd37..ffcc0bfc317 100644
--- a/src/support/stat.c
+++ b/src/support/stat.c
@@ -3,7 +3,7 @@
 #include "wt_internal.h"
 
 int
-__wt_stat_alloc_btree_stats(SESSION *session, WT_BTREE_STATS **statsp)
+__wt_stat_alloc_btree_stats(WT_SESSION_IMPL *session, WT_BTREE_STATS **statsp)
 {
 	WT_BTREE_STATS *stats;
 
@@ -61,7 +61,7 @@ __wt_stat_print_btree_stats(WT_BTREE_STATS *stats, FILE *stream)
 }
 
 int
-__wt_stat_alloc_btree_file_stats(SESSION *session, WT_BTREE_FILE_STATS **statsp)
+__wt_stat_alloc_btree_file_stats(WT_SESSION_IMPL *session, WT_BTREE_FILE_STATS **statsp)
 {
 	WT_BTREE_FILE_STATS *stats;
 
@@ -146,7 +146,7 @@ __wt_stat_print_btree_file_stats(WT_BTREE_FILE_STATS *stats, FILE *stream)
 }
 
 int
-__wt_stat_alloc_cache_stats(SESSION *session, WT_CACHE_STATS **statsp)
+__wt_stat_alloc_cache_stats(WT_SESSION_IMPL *session, WT_CACHE_STATS **statsp)
 {
 	WT_CACHE_STATS *stats;
 
@@ -198,7 +198,7 @@ __wt_stat_print_cache_stats(WT_CACHE_STATS *stats, FILE *stream)
 }
 
 int
-__wt_stat_alloc_conn_stats(SESSION *session, WT_CONN_STATS **statsp)
+__wt_stat_alloc_conn_stats(WT_SESSION_IMPL *session, WT_CONN_STATS **statsp)
 {
 	WT_CONN_STATS *stats;
 
@@ -244,7 +244,7 @@ __wt_stat_print_conn_stats(WT_CONN_STATS *stats, FILE *stream)
 }
 
 int
-__wt_stat_alloc_file_stats(SESSION *session, WT_FILE_STATS **statsp)
+__wt_stat_alloc_file_stats(WT_SESSION_IMPL *session, WT_FILE_STATS **statsp)
 {
 	WT_FILE_STATS *stats;