Change the default compression configuration to "uncompressed",

so the default is the fastest configuration.

4 files changed, 37 insertions, 31 deletions

diff --git a/dist/api_data.py b/dist/api_data.py
index 92f2726787a..ee0213ed15b 100644
--- a/dist/api_data.py
+++ b/dist/api_data.py
@@ -145,15 +145,13 @@ file_config = format_meta + [
 		do not ever evict the object's pages; see @ref
 		tuning_cache_resident for more information''',
 		type='boolean'),
-	Config('checksum', 'on', r'''
-		configure file block checksums; permitted values are
-		<code>on</code> (checksum all file blocks),
-		<code>off</code> (checksum no file blocks) and
-		<code>uncompresssed</code> (checksum only file blocks
-		which are not compressed for some reason).  The \c
-		uncompressed value is for applications which can
-		reasonably rely on decompression to fail if a block has
-		been corrupted''',
+	Config('checksum', 'uncompressed', r'''
+		configure block checksums; permitted values are <code>on</code>
+		(checksum all blocks), <code>off</code> (checksum no blocks) and
+		<code>uncompresssed</code> (checksum only blocks which are not
+		compressed for any reason).  The \c uncompressed setting is for
+		applications which can rely on decompression to fail if a block
+		has been corrupted''',
 		choices=['on', 'off', 'uncompressed']),
 	Config('collator', '', r'''
 		configure custom collation for keys.  Value must be a collator
diff --git a/src/config/config_def.c b/src/config/config_def.c
index 27b4fb721df..dada9471738 100644
--- a/src/config/config_def.c
+++ b/src/config/config_def.c
@@ -301,7 +301,7 @@ static const WT_CONFIG_ENTRY config_entries[] = {
 	},
 	{ "file.meta",
 	  "allocation_size=4KB,block_compressor=,cache_resident=0,checkpoint=,"
-	  "checksum=on,collator=,columns=,dictionary=0,format=btree,"
+	  "checksum=uncompressed,collator=,columns=,dictionary=0,format=btree,"
 	  "huffman_key=,huffman_value=,internal_item_max=0,"
 	  "internal_key_truncate=,internal_page_max=4KB,key_format=u,key_gap=10"
 	  ",leaf_item_max=0,leaf_page_max=1MB,memory_page_max=5MB,"
@@ -334,16 +334,17 @@ static const WT_CONFIG_ENTRY config_entries[] = {
 	  confchk_session_compact
 	},
 	{ "session.create",
-	  "allocation_size=4KB,block_compressor=,cache_resident=0,checksum=on,"
-	  "colgroups=,collator=,columns=,dictionary=0,exclusive=0,format=btree,"
-	  "huffman_key=,huffman_value=,internal_item_max=0,"
-	  "internal_key_truncate=,internal_page_max=4KB,key_format=u,key_gap=10"
-	  ",leaf_item_max=0,leaf_page_max=1MB,lsm_auto_throttle=,lsm_bloom=,"
-	  "lsm_bloom_bit_count=8,lsm_bloom_config=,lsm_bloom_hash_count=4,"
-	  "lsm_bloom_newest=0,lsm_bloom_oldest=0,lsm_chunk_size=2MB,"
-	  "lsm_merge_max=15,lsm_merge_threads=1,memory_page_max=5MB,"
-	  "os_cache_dirty_max=0,os_cache_max=0,prefix_compression=,source=,"
-	  "split_pct=75,type=file,value_format=u",
+	  "allocation_size=4KB,block_compressor=,cache_resident=0,"
+	  "checksum=uncompressed,colgroups=,collator=,columns=,dictionary=0,"
+	  "exclusive=0,format=btree,huffman_key=,huffman_value=,"
+	  "internal_item_max=0,internal_key_truncate=,internal_page_max=4KB,"
+	  "key_format=u,key_gap=10,leaf_item_max=0,leaf_page_max=1MB,"
+	  "lsm_auto_throttle=,lsm_bloom=,lsm_bloom_bit_count=8,"
+	  "lsm_bloom_config=,lsm_bloom_hash_count=4,lsm_bloom_newest=0,"
+	  "lsm_bloom_oldest=0,lsm_chunk_size=2MB,lsm_merge_max=15,"
+	  "lsm_merge_threads=1,memory_page_max=5MB,os_cache_dirty_max=0,"
+	  "os_cache_max=0,prefix_compression=,source=,split_pct=75,type=file,"
+	  "value_format=u",
 	  confchk_session_create
 	},
 	{ "session.drop",
diff --git a/src/docs/upgrading.dox b/src/docs/upgrading.dox
index 82115ce66dc..b438317f3ea 100644
--- a/src/docs/upgrading.dox
+++ b/src/docs/upgrading.dox
@@ -5,9 +5,8 @@
 
 <dt>Table of WiredTiger extension methods</dt>
 <dd>
-In the 1.6.2 release, new entries were added to the list of WiredTiger
-extension methods; applications using the extension methods will require
-recompilation.
+New functionality was added to the list of WiredTiger extension methods;
+applications using the extension methods will require recompilation.
 </dd>
 
 <dt>WT_SESSION::create no longer accepts a "source" configuration</dt>
@@ -17,6 +16,15 @@ Normal applications should not have been using it, and there were a number of
 bugs associated with it.
 </dd>
 
+<dt>Default checksum configuration</dt>
+<dd>
+The default file checksum configuration was changed to \c uncompressed,
+which means blocks that are compressed will no longer also include a
+checksum, by default.  Applications using compression insufficient for
+the purposes of corrupted block identification should change their file
+checksum configuration to \c on.
+</dd>
+
 </dl>
 <hr>
 @section version_161 Upgrading to Version 1.6.1
diff --git a/src/include/wiredtiger.in b/src/include/wiredtiger.in
index f80e5f45c0f..3b9350bb4ae 100644
--- a/src/include/wiredtiger.in
+++ b/src/include/wiredtiger.in
@@ -641,14 +641,13 @@ struct __wt_session {
 	 * @config{cache_resident, do not ever evict the object's pages; see
 	 * @ref tuning_cache_resident for more information., a boolean flag;
 	 * default \c false.}
-	 * @config{checksum, configure file block checksums; permitted values
-	 * are <code>on</code> (checksum all file blocks)\, <code>off</code>
-	 * (checksum no file blocks) and <code>uncompresssed</code> (checksum
-	 * only file blocks which are not compressed for some reason). The \c
-	 * uncompressed value is for applications which can reasonably rely on
-	 * decompression to fail if a block has been corrupted., a string\,
-	 * chosen from the following options: \c "on"\, \c "off"\, \c
-	 * "uncompressed"; default \c on.}
+	 * @config{checksum, configure block checksums; permitted values are
+	 * <code>on</code> (checksum all blocks)\, <code>off</code> (checksum no
+	 * blocks) and <code>uncompresssed</code> (checksum only blocks which
+	 * are not compressed for any reason). The \c uncompressed setting is
+	 * for applications which can rely on decompression to fail if a block
+	 * has been corrupted., a string\, chosen from the following options: \c
+	 * "on"\, \c "off"\, \c "uncompressed"; default \c uncompressed.}
 	 * @config{colgroups, comma-separated list of names of column groups.
 	 * Each column group is stored separately\, keyed by the primary key of
 	 * the table.  If no column groups are specified\, all columns are