Manual merge

include/my_base.h:
  Auto merged
include/my_global.h:
  Auto merged
include/my_sys.h:
  Auto merged
myisam/mi_check.c:
  Auto merged
myisam/mi_extra.c:
  Auto merged
myisam/mi_locking.c:
  Auto merged
myisam/myisamchk.c:
  Auto merged
myisam/myisamdef.h:
  Auto merged
mysql-test/r/key_cache.result:
  Auto merged
mysql-test/t/key_cache.test:
  Auto merged
sql/ha_myisam.cc:
  Auto merged
sql/handler.cc:
  Auto merged
sql/handler.h:
  Auto merged
sql/item_cmpfunc.h:
  Auto merged
sql/mysql_priv.h:
  Auto merged
sql/opt_range.cc:
  Auto merged
sql/set_var.h:
  Auto merged
sql/sql_base.cc:
  Auto merged
sql/sql_parse.cc:
  Auto merged
sql/sql_table.cc:
  Auto merged
sql/table.h:
  Auto merged

23 files changed, 244 insertions, 116 deletions

diff --git a/myisam/Makefile.am b/myisam/Makefile.am
index d4cd953ac66..fdcfc6d0d41 100644
--- a/myisam/Makefile.am
+++ b/myisam/Makefile.am
@@ -47,7 +47,7 @@ libmyisam_a_SOURCES =	mi_open.c mi_extra.c mi_info.c mi_rkey.c \
 			mi_range.c mi_dbug.c mi_checksum.c mi_log.c \
 			mi_changed.c mi_static.c mi_delete_all.c \
 			mi_delete_table.c mi_rename.c  mi_check.c \
-			mi_preload.c \
+			mi_keycache.c mi_preload.c \
 			ft_parser.c ft_stopwords.c ft_static.c \
 			ft_update.c ft_boolean_search.c ft_nlq_search.c sort.c \
 			rt_index.c rt_key.c rt_mbr.c rt_split.c sp_key.c
diff --git a/myisam/mi_check.c b/myisam/mi_check.c
index 60053674647..16fe5567d72 100644
--- a/myisam/mi_check.c
+++ b/myisam/mi_check.c
@@ -230,7 +230,9 @@ static int check_k_link(MI_CHECK *param, register MI_INFO *info, uint nr)
     if (next_link > info->state->key_file_length ||
 	next_link & (info->s->blocksize-1))
       DBUG_RETURN(1);
-    if (!(buff=key_cache_read(info->s->kfile, next_link, (byte*) info->buff,
+    if (!(buff=key_cache_read(*info->s->keycache,
+                              info->s->kfile, next_link, DFLT_INIT_HITS,
+                              (byte*) info->buff,
 			      myisam_block_size, block_size, 1)))
       DBUG_RETURN(1);
     next_link=mi_sizekorr(buff);
@@ -259,7 +261,8 @@ int chk_size(MI_CHECK *param, register MI_INFO *info)
 
   if (!(param->testflag & T_SILENT)) puts("- check file-size");
 
-  flush_key_blocks(info->s->kfile, FLUSH_FORCE_WRITE); /* If called externally */
+  flush_key_blocks(*info->s->keycache,
+                info->s->kfile, FLUSH_FORCE_WRITE); /* If called externally */
 
   size=my_seek(info->s->kfile,0L,MY_SEEK_END,MYF(0));
   if ((skr=(my_off_t) info->state->key_file_length) != size)
@@ -369,8 +372,8 @@ int chk_key(MI_CHECK *param, register MI_INFO *info)
     if (share->state.key_root[key] == HA_OFFSET_ERROR &&
 	(info->state->records == 0 || keyinfo->flag & HA_FULLTEXT))
       continue;
-    if (!_mi_fetch_keypage(info,keyinfo,share->state.key_root[key],info->buff,
-			   0))
+    if (!_mi_fetch_keypage(info,keyinfo,share->state.key_root[key],
+                           DFLT_INIT_HITS,info->buff,0))
     {
       mi_check_print_error(param,"Can't read indexpage from filepos: %s",
 		  llstr(share->state.key_root[key],buff));
@@ -548,7 +551,8 @@ static int chk_index(MI_CHECK *param, MI_INFO *info, MI_KEYDEF *keyinfo,
 	info->state->key_file_length=(max_length &
 				      ~ (my_off_t) (info->s->blocksize-1));
       }
-      if (!_mi_fetch_keypage(info,keyinfo,next_page,temp_buff,0))
+      if (!_mi_fetch_keypage(info,keyinfo,next_page,
+                             DFLT_INIT_HITS,temp_buff,0))
       {
 	mi_check_print_error(param,"Can't read key from filepos: %s",llstr(next_page,llbuff));
 	goto err;
@@ -1120,7 +1124,8 @@ int mi_repair(MI_CHECK *param, register MI_INFO *info,
   param->testflag|=T_REP; /* for easy checking */
 
   if (!param->using_global_keycache)
-    VOID(init_key_cache(param->use_buffers));
+    VOID(init_key_cache(dflt_keycache,dflt_key_cache_var.block_size,
+                        param->use_buffers,&dflt_key_cache_var));
 
   if (init_io_cache(&param->read_cache,info->dfile,
 		    (uint) param->read_buffer_length,
@@ -1441,7 +1446,8 @@ int movepoint(register MI_INFO *info, byte *record, my_off_t oldpos,
 	nod_flag=mi_test_if_nod(info->buff);
 	_mi_dpointer(info,info->int_keypos-nod_flag-
 		     info->s->rec_reflength,newpos);
-	if (_mi_write_keypage(info,keyinfo,info->last_keypage,info->buff))
+	if (_mi_write_keypage(info,keyinfo,info->last_keypage,
+                              DFLT_INIT_HITS,info->buff))
 	  DBUG_RETURN(-1);
       }
       else
@@ -1478,13 +1484,13 @@ void lock_memory(MI_CHECK *param __attribute__((unused)))
 
 int flush_blocks(MI_CHECK *param, File file)
 {
-  if (flush_key_blocks(file,FLUSH_RELEASE))
+  if (flush_key_blocks(*dflt_keycache,file,FLUSH_RELEASE))
   {
     mi_check_print_error(param,"%d when trying to write bufferts",my_errno);
     return(1);
   }
   if (!param->using_global_keycache)
-    end_key_cache();
+    end_key_cache(dflt_keycache,1);
   return 0;
 } /* flush_blocks */
 
@@ -1538,7 +1544,7 @@ int mi_sort_index(MI_CHECK *param, register MI_INFO *info, my_string name)
   }
 
   /* Flush key cache for this file if we are calling this outside myisamchk */
-  flush_key_blocks(share->kfile, FLUSH_IGNORE_CHANGED);
+  flush_key_blocks(*share->keycache,share->kfile, FLUSH_IGNORE_CHANGED);
 
   share->state.version=(ulong) time((time_t*) 0);
   old_state=share->state;			/* save state if not stored */
@@ -1598,7 +1604,7 @@ static int sort_one_index(MI_CHECK *param, MI_INFO *info, MI_KEYDEF *keyinfo,
     mi_check_print_error(param,"Not Enough memory");
     DBUG_RETURN(-1);
   }
-  if (!_mi_fetch_keypage(info,keyinfo,pagepos,buff,0))
+  if (!_mi_fetch_keypage(info,keyinfo,pagepos,DFLT_INIT_HITS,buff,0))
   {
     mi_check_print_error(param,"Can't read key block from filepos: %s",
 		llstr(pagepos,llbuff));
@@ -1844,7 +1850,7 @@ int mi_repair_by_sort(MI_CHECK *param, register MI_INFO *info,
       Flush key cache for this file if we are calling this outside
       myisamchk
     */
-    flush_key_blocks(share->kfile, FLUSH_IGNORE_CHANGED);
+    flush_key_blocks(*share->keycache,share->kfile, FLUSH_IGNORE_CHANGED);
     /* Clear the pointers to the given rows */
     for (i=0 ; i < share->base.keys ; i++)
       share->state.key_root[i]= HA_OFFSET_ERROR;
@@ -1854,7 +1860,7 @@ int mi_repair_by_sort(MI_CHECK *param, register MI_INFO *info,
   }
   else
   {
-    if (flush_key_blocks(share->kfile, FLUSH_FORCE_WRITE))
+    if (flush_key_blocks(*share->keycache,share->kfile, FLUSH_FORCE_WRITE))
       goto err;
     key_map= ~key_map;				/* Create the missing keys */
   }
@@ -2207,7 +2213,7 @@ int mi_repair_parallel(MI_CHECK *param, register MI_INFO *info,
       Flush key cache for this file if we are calling this outside
       myisamchk
     */
-    flush_key_blocks(share->kfile, FLUSH_IGNORE_CHANGED);
+    flush_key_blocks(*share->keycache,share->kfile, FLUSH_IGNORE_CHANGED);
     /* Clear the pointers to the given rows */
     for (i=0 ; i < share->base.keys ; i++)
       share->state.key_root[i]= HA_OFFSET_ERROR;
@@ -2217,7 +2223,7 @@ int mi_repair_parallel(MI_CHECK *param, register MI_INFO *info,
   }
   else
   {
-    if (flush_key_blocks(share->kfile, FLUSH_FORCE_WRITE))
+    if (flush_key_blocks(*share->keycache,share->kfile, FLUSH_FORCE_WRITE))
       goto err;
     key_map= ~key_map;				/* Create the missing keys */
   }
@@ -3332,13 +3338,13 @@ static int sort_insert_key(MI_SORT_PARAM *sort_param,
   bzero((byte*) anc_buff+key_block->last_length,
 	keyinfo->block_length- key_block->last_length);
   key_file_length=info->state->key_file_length;
-  if ((filepos=_mi_new(info,keyinfo)) == HA_OFFSET_ERROR)
+  if ((filepos=_mi_new(info,keyinfo,DFLT_INIT_HITS)) == HA_OFFSET_ERROR)
     DBUG_RETURN(1);
 
   /* If we read the page from the key cache, we have to write it back to it */
   if (key_file_length == info->state->key_file_length)
   {
-    if (_mi_write_keypage(info, keyinfo, filepos, anc_buff))
+    if (_mi_write_keypage(info, keyinfo, filepos, DFLT_INIT_HITS, anc_buff))
       DBUG_RETURN(1);
   }
   else if (my_pwrite(info->s->kfile,(byte*) anc_buff,
@@ -3436,13 +3442,14 @@ int flush_pending_blocks(MI_SORT_PARAM *sort_param)
       _mi_kpointer(info,key_block->end_pos,filepos);
     key_file_length=info->state->key_file_length;
     bzero((byte*) key_block->buff+length, keyinfo->block_length-length);
-    if ((filepos=_mi_new(info,keyinfo)) == HA_OFFSET_ERROR)
+    if ((filepos=_mi_new(info,keyinfo,DFLT_INIT_HITS)) == HA_OFFSET_ERROR)
       DBUG_RETURN(1);
 
     /* If we read the page from the key cache, we have to write it back */
     if (key_file_length == info->state->key_file_length)
     {
-      if (_mi_write_keypage(info, keyinfo, filepos, key_block->buff))
+      if (_mi_write_keypage(info, keyinfo, filepos,
+                            DFLT_INIT_HITS, key_block->buff))
 	DBUG_RETURN(1);
     }
     else if (my_pwrite(info->s->kfile,(byte*) key_block->buff,
diff --git a/myisam/mi_close.c b/myisam/mi_close.c
index dbaaebb1143..8e7fb497dfc 100644
--- a/myisam/mi_close.c
+++ b/myisam/mi_close.c
@@ -64,7 +64,7 @@ int mi_close(register MI_INFO *info)
   if (flag)
   {
     if (share->kfile >= 0 &&
-	flush_key_blocks(share->kfile,
+	flush_key_blocks(*share->keycache,share->kfile,
 			 share->temporary ? FLUSH_IGNORE_CHANGED :
 			 FLUSH_RELEASE))
       error=my_errno;
diff --git a/myisam/mi_delete.c b/myisam/mi_delete.c
index 2ab5c5d0319..5635e0a2139 100644
--- a/myisam/mi_delete.c
+++ b/myisam/mi_delete.c
@@ -155,7 +155,7 @@ static int _mi_ck_real_delete(register MI_INFO *info, MI_KEYDEF *keyinfo,
     DBUG_RETURN(my_errno=ENOMEM);
   }
   DBUG_PRINT("info",("root_page: %ld",old_root));
-  if (!_mi_fetch_keypage(info,keyinfo,old_root,root_buff,0))
+  if (!_mi_fetch_keypage(info,keyinfo,old_root,DFLT_INIT_HITS,root_buff,0))
   {
     error= -1;
     goto err;
@@ -179,11 +179,12 @@ static int _mi_ck_real_delete(register MI_INFO *info, MI_KEYDEF *keyinfo,
 	  *root=_mi_kpos(nod_flag,root_buff+2+nod_flag);
 	else
 	  *root=HA_OFFSET_ERROR;
-	if (_mi_dispose(info,keyinfo,old_root))
+	if (_mi_dispose(info,keyinfo,old_root,DFLT_INIT_HITS))
 	  error= -1;
       }
       else
-	error=_mi_write_keypage(info,keyinfo,old_root,root_buff);
+	error=_mi_write_keypage(info,keyinfo,old_root,
+                                DFLT_INIT_HITS,root_buff);
     }
   }
 err:
@@ -253,7 +254,7 @@ static int d_search(register MI_INFO *info, register MI_KEYDEF *keyinfo,
       {
         /* the last entry in sub-tree */
         DBUG_PRINT("info",("FT2: the last entry"));
-        _mi_dispose(info, keyinfo, root);
+        _mi_dispose(info, keyinfo, root,DFLT_INIT_HITS);
         /* fall through to normal delete */
       }
       else
@@ -268,7 +269,8 @@ static int d_search(register MI_INFO *info, register MI_KEYDEF *keyinfo,
         subkeys++;
         ft_intXstore(kpos, subkeys);
         if (!ret_value)
-          ret_value=_mi_write_keypage(info,keyinfo,page,anc_buff);
+          ret_value=_mi_write_keypage(info,keyinfo,page,
+                                      DFLT_INIT_HITS,anc_buff);
         DBUG_PRINT("exit",("Return: %d",ret_value));
         DBUG_RETURN(ret_value);
       }
@@ -287,7 +289,7 @@ static int d_search(register MI_INFO *info, register MI_KEYDEF *keyinfo,
       DBUG_PRINT("exit",("Return: %d",-1));
       DBUG_RETURN(-1);
     }
-    if (!_mi_fetch_keypage(info,keyinfo,leaf_page,leaf_buff,0))
+    if (!_mi_fetch_keypage(info,keyinfo,leaf_page,DFLT_INIT_HITS,leaf_buff,0))
       goto err;
   }
 
@@ -319,7 +321,7 @@ static int d_search(register MI_INFO *info, register MI_KEYDEF *keyinfo,
     mi_putint(anc_buff,length,nod_flag);
     if (!nod_flag)
     {						/* On leaf page */
-      if (_mi_write_keypage(info,keyinfo,page,anc_buff))
+      if (_mi_write_keypage(info,keyinfo,page,DFLT_INIT_HITS,anc_buff))
       {
         DBUG_PRINT("exit",("Return: %d",-1));
 	DBUG_RETURN(-1);
@@ -354,7 +356,7 @@ static int d_search(register MI_INFO *info, register MI_KEYDEF *keyinfo,
     ret_value=_mi_split_page(info,keyinfo,key,anc_buff,lastkey,0) | 2;
   }
   if (save_flag && ret_value != 1)
-    ret_value|=_mi_write_keypage(info,keyinfo,page,anc_buff);
+    ret_value|=_mi_write_keypage(info,keyinfo,page,DFLT_INIT_HITS,anc_buff);
   else
   {
     DBUG_DUMP("page",(byte*) anc_buff,mi_getint(anc_buff));
@@ -398,7 +400,7 @@ static int del(register MI_INFO *info, register MI_KEYDEF *keyinfo, uchar *key,
     if (!(next_buff= (uchar*) my_alloca((uint) keyinfo->block_length+
 					MI_MAX_KEY_BUFF*2)))
       DBUG_RETURN(-1);
-    if (!_mi_fetch_keypage(info,keyinfo,next_page,next_buff,0))
+    if (!_mi_fetch_keypage(info,keyinfo,next_page,DFLT_INIT_HITS,next_buff,0))
       ret_value= -1;
     else
     {
@@ -426,7 +428,7 @@ static int del(register MI_INFO *info, register MI_KEYDEF *keyinfo, uchar *key,
 			       (uchar*) 0,(uchar*) 0,(my_off_t) 0,0);
 	}
       }
-      if (_mi_write_keypage(info,keyinfo,leaf_page,leaf_buff))
+      if (_mi_write_keypage(info,keyinfo,leaf_page,DFLT_INIT_HITS,leaf_buff))
 	goto err;
     }
     my_afree((byte*) next_buff);
@@ -436,7 +438,7 @@ static int del(register MI_INFO *info, register MI_KEYDEF *keyinfo, uchar *key,
 	/* Remove last key from leaf page */
 
   mi_putint(leaf_buff,key_start-leaf_buff,nod_flag);
-  if (_mi_write_keypage(info,keyinfo,leaf_page,leaf_buff))
+  if (_mi_write_keypage(info,keyinfo,leaf_page,DFLT_INIT_HITS,leaf_buff))
     goto err;
 
 	/* Place last key in ancestor page on deleted key position */
@@ -524,7 +526,7 @@ static int underflow(register MI_INFO *info, register MI_KEYDEF *keyinfo,
       goto err;
     }
     next_page= _mi_kpos(key_reflength,next_keypos);
-    if (!_mi_fetch_keypage(info,keyinfo,next_page,buff,0))
+    if (!_mi_fetch_keypage(info,keyinfo,next_page,DFLT_INIT_HITS,buff,0))
       goto err;
     buff_length=mi_getint(buff);
     DBUG_DUMP("next",(byte*) buff,buff_length);
@@ -563,7 +565,7 @@ static int underflow(register MI_INFO *info, register MI_KEYDEF *keyinfo,
     if (buff_length <= keyinfo->block_length)
     {						/* Keys in one page */
       memcpy((byte*) leaf_buff,(byte*) buff,(size_t) buff_length);
-      if (_mi_dispose(info,keyinfo,next_page))
+      if (_mi_dispose(info,keyinfo,next_page,DFLT_INIT_HITS))
        goto err;
     }
     else
@@ -612,10 +614,10 @@ static int underflow(register MI_INFO *info, register MI_KEYDEF *keyinfo,
       (*keyinfo->store_key)(keyinfo,buff+p_length,&s_temp);
       mi_putint(buff,length+t_length+p_length,nod_flag);
 
-      if (_mi_write_keypage(info,keyinfo,next_page,buff))
+      if (_mi_write_keypage(info,keyinfo,next_page,DFLT_INIT_HITS,buff))
 	goto err;
     }
-    if (_mi_write_keypage(info,keyinfo,leaf_page,leaf_buff))
+    if (_mi_write_keypage(info,keyinfo,leaf_page,DFLT_INIT_HITS,leaf_buff))
       goto err;
     DBUG_RETURN(anc_length <= ((info->quick_mode ? MI_MIN_BLOCK_LENGTH :
 				(uint) keyinfo->underflow_block_length)));
@@ -627,7 +629,7 @@ static int underflow(register MI_INFO *info, register MI_KEYDEF *keyinfo,
   if (!keypos)
     goto err;
   next_page= _mi_kpos(key_reflength,keypos);
-  if (!_mi_fetch_keypage(info,keyinfo,next_page,buff,0))
+  if (!_mi_fetch_keypage(info,keyinfo,next_page,DFLT_INIT_HITS,buff,0))
       goto err;
   buff_length=mi_getint(buff);
   endpos=buff+buff_length;
@@ -671,7 +673,7 @@ static int underflow(register MI_INFO *info, register MI_KEYDEF *keyinfo,
 
   if (buff_length <= keyinfo->block_length)
   {						/* Keys in one page */
-    if (_mi_dispose(info,keyinfo,leaf_page))
+    if (_mi_dispose(info,keyinfo,leaf_page,DFLT_INIT_HITS))
       goto err;
   }
   else
@@ -718,11 +720,11 @@ static int underflow(register MI_INFO *info, register MI_KEYDEF *keyinfo,
 	  (size_t) length);
     (*keyinfo->store_key)(keyinfo,leaf_buff+p_length,&s_temp);
     mi_putint(leaf_buff,length+t_length+p_length,nod_flag);
-    if (_mi_write_keypage(info,keyinfo,leaf_page,leaf_buff))
+    if (_mi_write_keypage(info,keyinfo,leaf_page,DFLT_INIT_HITS,leaf_buff))
       goto err;
     mi_putint(buff,endpos-buff,nod_flag);
   }
-  if (_mi_write_keypage(info,keyinfo,next_page,buff))
+  if (_mi_write_keypage(info,keyinfo,next_page,DFLT_INIT_HITS,buff))
     goto err;
   DBUG_RETURN(anc_length <= (uint) keyinfo->block_length/2);
 err:
diff --git a/myisam/mi_delete_all.c b/myisam/mi_delete_all.c
index 45e56626d59..99873661feb 100644
--- a/myisam/mi_delete_all.c
+++ b/myisam/mi_delete_all.c
@@ -53,7 +53,7 @@ int mi_delete_all_rows(MI_INFO *info)
     If we are using delayed keys or if the user has done changes to the tables
     since it was locked then there may be key blocks in the key cache
   */
-  flush_key_blocks(share->kfile, FLUSH_IGNORE_CHANGED);
+  flush_key_blocks(*share->keycache, share->kfile, FLUSH_IGNORE_CHANGED);
   if (my_chsize(info->dfile, 0, 0, MYF(MY_WME)) ||
       my_chsize(share->kfile, share->base.keystart, 0, MYF(MY_WME))  )
     goto err;
diff --git a/myisam/mi_extra.c b/myisam/mi_extra.c
index c86ca1c2e7b..1d57e0c0e18 100644
--- a/myisam/mi_extra.c
+++ b/myisam/mi_extra.c
@@ -283,7 +283,7 @@ int mi_extra(MI_INFO *info, enum ha_extra_function function, void *extra_arg)
 #ifdef __WIN__
     /* Close the isam and data files as Win32 can't drop an open table */
     pthread_mutex_lock(&share->intern_lock);
-    if (flush_key_blocks(share->kfile,
+    if (flush_key_blocks(*share->keycache, share->kfile,
 			 (function == HA_EXTRA_FORCE_REOPEN ?
 			  FLUSH_RELEASE : FLUSH_IGNORE_CHANGED)))
     {
@@ -329,7 +329,7 @@ int mi_extra(MI_INFO *info, enum ha_extra_function function, void *extra_arg)
     break;
   case HA_EXTRA_FLUSH:
     if (!share->temporary)
-      flush_key_blocks(share->kfile,FLUSH_KEEP);
+      flush_key_blocks(*share->keycache,share->kfile,FLUSH_KEEP);
 #ifdef HAVE_PWRITE
     _mi_decrement_open_count(info);
 #endif
@@ -374,6 +374,9 @@ int mi_extra(MI_INFO *info, enum ha_extra_function function, void *extra_arg)
   case HA_EXTRA_PRELOAD_BUFFER_SIZE:
     info->preload_buff_size= *((ulong *) extra_arg); 
     break;
+  case HA_EXTRA_SET_KEY_CACHE:
+    share->reg_keycache= share->keycache= (KEY_CACHE_HANDLE *) extra_arg;
+    break;
   case HA_EXTRA_KEY_CACHE:
   case HA_EXTRA_NO_KEY_CACHE:
   default:
diff --git a/myisam/mi_keycache.c b/myisam/mi_keycache.c
new file mode 100644
index 00000000000..1010aef9e1d
--- /dev/null
+++ b/myisam/mi_keycache.c
@@ -0,0 +1,63 @@
+/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
+
+/*
+  Key cache assignments
+*/
+
+#include "myisamdef.h"
+
+
+/*
+  Assign pages of the index file for a table to a key cache
+
+  SYNOPSIS
+    mi_assign_to_keycache()
+      info          open table
+      map           map of indexes to assign to the key cache 
+      key_cache_ptr pointer to the key cache handle
+
+  RETURN VALUE
+    0 if a success. error code - otherwise.
+
+  NOTES.
+    At present pages for all indexes must be assigned to the same key cache.
+    In future only pages for indexes specified in the key_map parameter
+    of the table will be assigned to the specified key cache.
+*/
+
+int mi_assign_to_keycache(MI_INFO *info, ulonglong key_map, 
+                          KEY_CACHE_HANDLE *reg_keycache)
+{
+  int error= 0;
+  MYISAM_SHARE* share= info->s;
+
+  DBUG_ENTER("mi_assign_to_keycache");
+
+  share->reg_keycache= reg_keycache;
+  if (!(info->lock_type == F_WRLCK && share->w_locks))
+  {
+    if (flush_key_blocks(*share->keycache, share->kfile, FLUSH_RELEASE))
+    {
+      error=my_errno;
+      mi_mark_crashed(info);		/* Mark that table must be checked */
+    }
+    share->keycache= reg_keycache;
+  }
+    
+  DBUG_RETURN(error);
+}
+
diff --git a/myisam/mi_locking.c b/myisam/mi_locking.c
index 22772a3dd2e..14d0b60741f 100644
--- a/myisam/mi_locking.c
+++ b/myisam/mi_locking.c
@@ -34,6 +34,7 @@ int mi_lock_database(MI_INFO *info, int lock_type)
   uint count;
   MYISAM_SHARE *share=info->s;
   uint flag;
+  uint switch_fl= 0;
   DBUG_ENTER("mi_lock_database");
 
   if (share->options & HA_OPTION_READ_ONLY_DATA ||
@@ -58,12 +59,26 @@ int mi_lock_database(MI_INFO *info, int lock_type)
       else
 	count= --share->w_locks;
       --share->tot_locks;
+      /*
+         During a key cache reassignment the current and registered
+         key caches for the table are different.
+         Although at present key cache ressignment is always
+         performed with a shared cache for the table acquired,
+         for future possible optimizations we still
+         handle this situation as if we could come to this point 
+         during the ressignment (in non-reassignment thread).
+      */ 
       if (info->lock_type == F_WRLCK && !share->w_locks &&
-	  !share->delay_key_write && flush_key_blocks(share->kfile,FLUSH_KEEP))
+	  ((switch_fl= share->keycache != share->reg_keycache) ||
+           !share->delay_key_write) && 
+           flush_key_blocks(*share->keycache, share->kfile,
+                            switch_fl ? FLUSH_RELEASE : FLUSH_KEEP))
       {
 	error=my_errno;
 	mi_mark_crashed(info);		/* Mark that table must be checked */
       }
+      if (switch_fl)
+        share->keycache= share->reg_keycache;
       if (info->opt_flag & (READ_CACHE_USED | WRITE_CACHE_USED))
       {
 	if (end_io_cache(&info->rec_cache))
@@ -393,7 +408,7 @@ int _mi_test_if_changed(register MI_INFO *info)
   {						/* Keyfile has changed */
     DBUG_PRINT("info",("index file changed"));
     if (share->state.process != share->this_process)
-      VOID(flush_key_blocks(share->kfile,FLUSH_RELEASE));
+      VOID(flush_key_blocks(*share->keycache,share->kfile,FLUSH_RELEASE));
     share->last_process=share->state.process;
     info->last_unique=	share->state.unique;
     info->last_loop=	share->state.update_count;
diff --git a/myisam/mi_page.c b/myisam/mi_page.c
index 49f3243e08d..72aaac5d381 100644
--- a/myisam/mi_page.c
+++ b/myisam/mi_page.c
@@ -24,14 +24,16 @@
 	/* Fetch a key-page in memory */
 
 uchar *_mi_fetch_keypage(register MI_INFO *info, MI_KEYDEF *keyinfo,
-			 my_off_t page, uchar *buff, int return_buffer)
+			 my_off_t page, int level, 
+                         uchar *buff, int return_buffer)
 {
   uchar *tmp;
   uint page_size;
   DBUG_ENTER("_mi_fetch_keypage");
   DBUG_PRINT("enter",("page: %ld",page));
 
-  tmp=(uchar*) key_cache_read(info->s->kfile,page,(byte*) buff,
+  tmp=(uchar*) key_cache_read(*info->s->keycache,
+                             info->s->kfile, page, level, (byte*) buff,
 			     (uint) keyinfo->block_length,
 			     (uint) keyinfo->block_length,
 			     return_buffer);
@@ -61,7 +63,7 @@ uchar *_mi_fetch_keypage(register MI_INFO *info, MI_KEYDEF *keyinfo,
 	/* Write a key-page on disk */
 
 int _mi_write_keypage(register MI_INFO *info, register MI_KEYDEF *keyinfo,
-		      my_off_t page, uchar *buff)
+		      my_off_t page, int level, uchar *buff)
 {
   reg3 uint length;
   DBUG_ENTER("_mi_write_keypage");
@@ -92,7 +94,8 @@ int _mi_write_keypage(register MI_INFO *info, register MI_KEYDEF *keyinfo,
     length=keyinfo->block_length;
   }
 #endif
-  DBUG_RETURN((key_cache_write(info->s->kfile,page,(byte*) buff,length,
+  DBUG_RETURN((key_cache_write(*info->s->keycache,
+                         info->s->kfile,page, level, (byte*) buff,length,
 			 (uint) keyinfo->block_length,
 			 (int) ((info->lock_type != F_UNLCK) ||
 				info->s->delay_key_write))));
@@ -101,7 +104,8 @@ int _mi_write_keypage(register MI_INFO *info, register MI_KEYDEF *keyinfo,
 
 	/* Remove page from disk */
 
-int _mi_dispose(register MI_INFO *info, MI_KEYDEF *keyinfo, my_off_t pos)
+int _mi_dispose(register MI_INFO *info, MI_KEYDEF *keyinfo, my_off_t pos,
+                int level)
 {
   my_off_t old_link;
   char buff[8];
@@ -112,7 +116,8 @@ int _mi_dispose(register MI_INFO *info, MI_KEYDEF *keyinfo, my_off_t pos)
   info->s->state.key_del[keyinfo->block_size]=pos;
   mi_sizestore(buff,old_link);
   info->s->state.changed|= STATE_NOT_SORTED_PAGES;
-  DBUG_RETURN(key_cache_write(info->s->kfile,pos,buff,
+  DBUG_RETURN(key_cache_write(*info->s->keycache,
+                              info->s->kfile, pos , level, buff,
 			      sizeof(buff),
 			      (uint) keyinfo->block_length,
 			      (int) (info->lock_type != F_UNLCK)));
@@ -121,7 +126,7 @@ int _mi_dispose(register MI_INFO *info, MI_KEYDEF *keyinfo, my_off_t pos)
 
 	/* Make new page on disk */
 
-my_off_t _mi_new(register MI_INFO *info, MI_KEYDEF *keyinfo)
+my_off_t _mi_new(register MI_INFO *info, MI_KEYDEF *keyinfo, int level)
 {
   my_off_t pos;
   char buff[8];
@@ -140,7 +145,8 @@ my_off_t _mi_new(register MI_INFO *info, MI_KEYDEF *keyinfo)
   }
   else
   {
-    if (!key_cache_read(info->s->kfile,pos,
+    if (!key_cache_read(*info->s->keycache,
+                        info->s->kfile, pos, level,
 			buff,
 			(uint) sizeof(buff),
 			(uint) keyinfo->block_length,0))
diff --git a/myisam/mi_panic.c b/myisam/mi_panic.c
index bd0b07b097e..f1d1d839fcd 100644
--- a/myisam/mi_panic.c
+++ b/myisam/mi_panic.c
@@ -48,7 +48,7 @@ int mi_panic(enum ha_panic_function flag)
       if (info->s->options & HA_OPTION_READ_ONLY_DATA)
 	break;
 #endif
-      if (flush_key_blocks(info->s->kfile,FLUSH_RELEASE))
+      if (flush_key_blocks(*info->s->keycache,info->s->kfile,FLUSH_RELEASE))
 	error=my_errno;
       if (info->opt_flag & WRITE_CACHE_USED)
 	if (flush_io_cache(&info->rec_cache))
diff --git a/myisam/mi_preload.c b/myisam/mi_preload.c
index a5d9bec160e..dc4fff5700a 100644
--- a/myisam/mi_preload.c
+++ b/myisam/mi_preload.c
@@ -69,7 +69,7 @@ int mi_preload(MI_INFO *info, ulonglong key_map, my_bool ignore_leaves)
   if (!(buff= (uchar *) my_malloc(length, MYF(MY_WME))))
     DBUG_RETURN(my_errno= HA_ERR_OUT_OF_MEM);
 
-  if (flush_key_blocks(share->kfile, FLUSH_RELEASE))
+  if (flush_key_blocks(*share->keycache,share->kfile, FLUSH_RELEASE))
     goto err;
  
   do
@@ -87,7 +87,9 @@ int mi_preload(MI_INFO *info, ulonglong key_map, my_bool ignore_leaves)
       {
         if (mi_test_if_nod(buff))
         {
-          if (key_cache_insert(share->kfile, pos, (byte*) buff, block_length))
+          if (key_cache_insert(*share->keycache,
+                               share->kfile, pos, DFLT_INIT_HITS, 
+                              (byte*) buff, block_length))
 	    goto err;
 	}
         pos+= block_length;
@@ -97,7 +99,9 @@ int mi_preload(MI_INFO *info, ulonglong key_map, my_bool ignore_leaves)
     }
     else
     {
-      if (key_cache_insert(share->kfile, pos, (byte*) buff, length))
+      if (key_cache_insert(*share->keycache,
+                           share->kfile, pos, DFLT_INIT_HITS,
+                           (byte*) buff, length))
 	goto err;
       pos+= length;
     }
diff --git a/myisam/mi_range.c b/myisam/mi_range.c
index 379ffba135a..caa57ce6187 100644
--- a/myisam/mi_range.c
+++ b/myisam/mi_range.c
@@ -142,7 +142,7 @@ static double _mi_search_pos(register MI_INFO *info,
   if (pos == HA_OFFSET_ERROR)
     DBUG_RETURN(0.5);
 
-  if (!(buff=_mi_fetch_keypage(info,keyinfo,pos,info->buff,1)))
+  if (!(buff=_mi_fetch_keypage(info,keyinfo,pos,DFLT_INIT_HITS,info->buff,1)))
     goto err;
   flag=(*keyinfo->bin_search)(info,keyinfo,buff,key,key_len,nextflag,
 			      &keypos,info->lastkey, &after_key);
diff --git a/myisam/mi_search.c b/myisam/mi_search.c
index 7e8577c0656..c2168d97cfe 100644
--- a/myisam/mi_search.c
+++ b/myisam/mi_search.c
@@ -76,7 +76,7 @@ int _mi_search(register MI_INFO *info, register MI_KEYDEF *keyinfo,
     DBUG_RETURN(1);                             /* Search at upper levels */
   }
 
-  if (!(buff=_mi_fetch_keypage(info,keyinfo,pos,info->buff,
+  if (!(buff=_mi_fetch_keypage(info,keyinfo,pos,DFLT_INIT_HITS,info->buff,
                                test(!(nextflag & SEARCH_SAVE_BUFF)))))
     goto err;
   DBUG_DUMP("page",(byte*) buff,mi_getint(buff));
@@ -119,7 +119,7 @@ int _mi_search(register MI_INFO *info, register MI_KEYDEF *keyinfo,
   if (pos != info->last_keypage)
   {
     uchar *old_buff=buff;
-    if (!(buff=_mi_fetch_keypage(info,keyinfo,pos,info->buff,
+    if (!(buff=_mi_fetch_keypage(info,keyinfo,pos,DFLT_INIT_HITS,info->buff,
                                  test(!(nextflag & SEARCH_SAVE_BUFF)))))
       goto err;
     keypos=buff+(keypos-old_buff);
@@ -1105,7 +1105,7 @@ int _mi_search_next(register MI_INFO *info, register MI_KEYDEF *keyinfo,
   if (info->buff_used)
   {
     if (!_mi_fetch_keypage(info,keyinfo,info->last_search_keypage,
-                           info->buff,0))
+                           DFLT_INIT_HITS,info->buff,0))
       DBUG_RETURN(-1);
     info->buff_used=0;
   }
@@ -1174,7 +1174,7 @@ int _mi_search_first(register MI_INFO *info, register MI_KEYDEF *keyinfo,
 
   do
   {
-    if (!_mi_fetch_keypage(info,keyinfo,pos,info->buff,0))
+    if (!_mi_fetch_keypage(info,keyinfo,pos,DFLT_INIT_HITS,info->buff,0))
     {
       info->lastpos= HA_OFFSET_ERROR;
       DBUG_RETURN(-1);
@@ -1217,7 +1217,7 @@ int _mi_search_last(register MI_INFO *info, register MI_KEYDEF *keyinfo,
   buff=info->buff;
   do
   {
-    if (!_mi_fetch_keypage(info,keyinfo,pos,buff,0))
+    if (!_mi_fetch_keypage(info,keyinfo,pos,DFLT_INIT_HITS,buff,0))
     {
       info->lastpos= HA_OFFSET_ERROR;
       DBUG_RETURN(-1);
diff --git a/myisam/mi_test1.c b/myisam/mi_test1.c
index 5a6818b8a3e..ec68e23c0c2 100644
--- a/myisam/mi_test1.c
+++ b/myisam/mi_test1.c
@@ -50,7 +50,7 @@ int main(int argc,char *argv[])
   MY_INIT(argv[0]);
   my_init();
   if (key_cacheing)
-    init_key_cache(IO_SIZE*16);
+    init_key_cache(dflt_keycache,512,IO_SIZE*16,0);
   get_options(argc,argv);
 
   exit(run_test("test1"));
diff --git a/myisam/mi_test2.c b/myisam/mi_test2.c
index 8dc279b6d97..61a14adf1ce 100644
--- a/myisam/mi_test2.c
+++ b/myisam/mi_test2.c
@@ -49,6 +49,7 @@ static	int verbose=0,testflag=0,
 static int pack_seg=HA_SPACE_PACK,pack_type=HA_PACK_KEY,remove_count=-1,
 	   create_flag=0;
 static ulong key_cache_size=IO_SIZE*16;
+static uint key_cache_block_size=IO_SIZE;
 
 static uint keys=MYISAM_KEYS,recant=1000;
 static uint use_blob=0;
@@ -214,7 +215,7 @@ int main(int argc, char *argv[])
   if (!silent)
     printf("- Writing key:s\n");
   if (key_cacheing)
-    init_key_cache(key_cache_size);		/* Use a small cache */
+    init_key_cache(dflt_keycache,key_cache_block_size,key_cache_size,0);		/* Use a small cache */
   if (locking)
     mi_lock_database(file,F_WRLCK);
   if (write_cacheing)
@@ -274,7 +275,7 @@ int main(int argc, char *argv[])
       goto end;
     }
     if (key_cacheing)
-      resize_key_cache(key_cache_size*2);
+      resize_key_cache(dflt_keycache,key_cache_block_size,key_cache_size*2);
   }
 
   if (!silent)
@@ -816,16 +817,19 @@ end:
       puts("Locking used");
     if (use_blob)
       puts("blobs used");
+#if 0
     printf("key cache status: \n\
 blocks used:%10lu\n\
 w_requests: %10lu\n\
 writes:     %10lu\n\
 r_requests: %10lu\n\
 reads:      %10lu\n",
-	   my_blocks_used, my_cache_w_requests, my_cache_write,
+	   my_blocks_used,
+           my_cache_w_requests, my_cache_write,
 	   my_cache_r_requests, my_cache_read);
+#endif
   }
-  end_key_cache();
+  end_key_cache(dflt_keycache,1);
   if (blob_buffer)
     my_free(blob_buffer,MYF(0));
   my_end(silent ? MY_CHECK_ERROR : MY_CHECK_ERROR | MY_GIVE_INFO);
diff --git a/myisam/mi_test3.c b/myisam/mi_test3.c
index 63cea4f715d..866c6299fac 100644
--- a/myisam/mi_test3.c
+++ b/myisam/mi_test3.c
@@ -177,7 +177,7 @@ void start_test(int id)
     exit(1);
   }
   if (key_cacheing && rnd(2) == 0)
-    init_key_cache(65536L);
+    init_key_cache(dflt_keycache,512,65536L,0);
   printf("Process %d, pid: %d\n",id,getpid()); fflush(stdout);
 
   for (error=i=0 ; i < tests && !error; i++)
diff --git a/myisam/mi_write.c b/myisam/mi_write.c
index 6985dac7832..8c08d6f179e 100644
--- a/myisam/mi_write.c
+++ b/myisam/mi_write.c
@@ -290,8 +290,8 @@ int _mi_enlarge_root(MI_INFO *info, MI_KEYDEF *keyinfo, uchar *key,
   mi_putint(info->buff,t_length+2+nod_flag,nod_flag);
   (*keyinfo->store_key)(keyinfo,info->buff+2+nod_flag,&s_temp);
   info->buff_used=info->page_changed=1;		/* info->buff is used */
-  if ((*root= _mi_new(info,keyinfo)) == HA_OFFSET_ERROR ||
-      _mi_write_keypage(info,keyinfo,*root,info->buff))
+  if ((*root= _mi_new(info,keyinfo,DFLT_INIT_HITS)) == HA_OFFSET_ERROR ||
+      _mi_write_keypage(info,keyinfo,*root,DFLT_INIT_HITS,info->buff))
     DBUG_RETURN(-1);
   DBUG_RETURN(0);
 } /* _mi_enlarge_root */
@@ -322,7 +322,7 @@ static int w_search(register MI_INFO *info, register MI_KEYDEF *keyinfo,
   if (!(temp_buff= (uchar*) my_alloca((uint) keyinfo->block_length+
 				      MI_MAX_KEY_BUFF*2)))
     DBUG_RETURN(-1);
-  if (!_mi_fetch_keypage(info,keyinfo,page,temp_buff,0))
+  if (!_mi_fetch_keypage(info,keyinfo,page,DFLT_INIT_HITS,temp_buff,0))
     goto err;
 
   flag=(*keyinfo->bin_search)(info,keyinfo,temp_buff,key,search_key_length,
@@ -368,7 +368,7 @@ static int w_search(register MI_INFO *info, register MI_KEYDEF *keyinfo,
         subkeys--; /* should there be underflow protection ? */
         ft_intXstore(keypos, subkeys);
         if (!error)
-          error=_mi_write_keypage(info,keyinfo,page,temp_buff);
+          error=_mi_write_keypage(info,keyinfo,page,DFLT_INIT_HITS,temp_buff);
         my_afree((byte*) temp_buff);
         DBUG_RETURN(error);
       }
@@ -391,7 +391,7 @@ static int w_search(register MI_INFO *info, register MI_KEYDEF *keyinfo,
   {
     error=_mi_insert(info,keyinfo,key,temp_buff,keypos,keybuff,father_buff,
 		     father_keypos,father_page, insert_last);
-    if (_mi_write_keypage(info,keyinfo,page,temp_buff))
+    if (_mi_write_keypage(info,keyinfo,page,DFLT_INIT_HITS,temp_buff))
       goto err;
   }
   my_afree((byte*) temp_buff);
@@ -515,7 +515,7 @@ int _mi_split_page(register MI_INFO *info, register MI_KEYDEF *keyinfo,
   }
 
 	/* Move middle item to key and pointer to new page */
-  if ((new_pos=_mi_new(info,keyinfo)) == HA_OFFSET_ERROR)
+  if ((new_pos=_mi_new(info,keyinfo,DFLT_INIT_HITS)) == HA_OFFSET_ERROR)
     DBUG_RETURN(-1);
   _mi_kpointer(info,_mi_move_key(keyinfo,key,key_buff),new_pos);
 
@@ -531,7 +531,7 @@ int _mi_split_page(register MI_INFO *info, register MI_KEYDEF *keyinfo,
   (*keyinfo->store_key)(keyinfo,info->buff+key_ref_length,&s_temp);
   mi_putint(info->buff,length+t_length+key_ref_length,nod_flag);
 
-  if (_mi_write_keypage(info,keyinfo,new_pos,info->buff))
+  if (_mi_write_keypage(info,keyinfo,new_pos,DFLT_INIT_HITS,info->buff))
     DBUG_RETURN(-1);
   DBUG_DUMP("key",(byte*) key,_mi_keylength(keyinfo,key));
   DBUG_RETURN(2);				/* Middle key up */
@@ -682,7 +682,7 @@ static int _mi_balance_page(register MI_INFO *info, MI_KEYDEF *keyinfo,
     DBUG_PRINT("test",("use left page: %lu",next_page));
   }					/* father_key_pos ptr to parting key */
 
-  if (!_mi_fetch_keypage(info,keyinfo,next_page,info->buff,0))
+  if (!_mi_fetch_keypage(info,keyinfo,next_page,DFLT_INIT_HITS,info->buff,0))
     goto err;
   DBUG_DUMP("next",(byte*) info->buff,mi_getint(info->buff));
 
@@ -722,8 +722,8 @@ static int _mi_balance_page(register MI_INFO *info, MI_KEYDEF *keyinfo,
       memcpy((byte*) buff+2,(byte*) pos+k_length,(size_t) length);
     }
 
-    if (_mi_write_keypage(info,keyinfo,next_page,info->buff) ||
-	_mi_write_keypage(info,keyinfo,father_page,father_buff))
+    if (_mi_write_keypage(info,keyinfo,next_page,DFLT_INIT_HITS,info->buff) ||
+	_mi_write_keypage(info,keyinfo,father_page,DFLT_INIT_HITS,father_buff))
       goto err;
     DBUG_RETURN(0);
   }
@@ -763,12 +763,13 @@ static int _mi_balance_page(register MI_INFO *info, MI_KEYDEF *keyinfo,
   memcpy((byte*) (right ? key : father_key_pos),pos,(size_t) k_length);
   memcpy((byte*) (right ? father_key_pos : key),tmp_part_key, k_length);
 
-  if ((new_pos=_mi_new(info,keyinfo)) == HA_OFFSET_ERROR)
+  if ((new_pos=_mi_new(info,keyinfo,DFLT_INIT_HITS)) == HA_OFFSET_ERROR)
     goto err;
   _mi_kpointer(info,key+k_length,new_pos);
   if (_mi_write_keypage(info,keyinfo,(right ? new_pos : next_page),
-			info->buff) ||
-      _mi_write_keypage(info,keyinfo,(right ? next_page : new_pos),extra_buff))
+			DFLT_INIT_HITS,info->buff) ||
+      _mi_write_keypage(info,keyinfo,(right ? next_page : new_pos),
+                        DFLT_INIT_HITS,extra_buff))
     goto err;
 
   DBUG_RETURN(1);				/* Middle key up */
diff --git a/myisam/myisamchk.c b/myisam/myisamchk.c
index 43ade35bfd5..63d61af774b 100644
--- a/myisam/myisamchk.c
+++ b/myisam/myisamchk.c
@@ -44,6 +44,7 @@ static const char *load_default_groups[]= { "myisamchk", 0 };
 static const char *set_charset_name, *opt_tmpdir;
 static CHARSET_INFO *set_charset;
 static long opt_myisam_block_size;
+static long opt_key_cache_block_size;
 static const char *my_progname_short;
 static int stopwords_inited= 0;
 static MY_TMPDIR myisamchk_tmpdir;
@@ -148,7 +149,8 @@ int main(int argc, char **argv)
 
 enum options {
   OPT_CHARSETS_DIR=256, OPT_SET_CHARSET,OPT_START_CHECK_POS,
-  OPT_CORRECT_CHECKSUM, OPT_KEY_BUFFER_SIZE, OPT_MYISAM_BLOCK_SIZE,
+  OPT_CORRECT_CHECKSUM, OPT_KEY_BUFFER_SIZE,
+  OPT_KEY_CACHE_BLOCK_SIZE, OPT_MYISAM_BLOCK_SIZE,
   OPT_READ_BUFFER_SIZE, OPT_WRITE_BUFFER_SIZE, OPT_SORT_BUFFER_SIZE,
   OPT_SORT_KEY_BLOCKS, OPT_DECODE_BITS, OPT_FT_MIN_WORD_LEN,
   OPT_FT_MAX_WORD_LEN, OPT_FT_MAX_WORD_LEN_FOR_SORT
@@ -283,6 +285,11 @@ static struct my_option my_long_options[] =
     (gptr*) &check_param.use_buffers, (gptr*) &check_param.use_buffers, 0,
     GET_ULONG, REQUIRED_ARG, (long) USE_BUFFER_INIT, (long) MALLOC_OVERHEAD,
     (long) ~0L, (long) MALLOC_OVERHEAD, (long) IO_SIZE, 0},
+  { "key_cache_block_size", OPT_KEY_CACHE_BLOCK_SIZE,  "",
+    (gptr*) &opt_key_cache_block_size,
+    (gptr*) &opt_key_cache_block_size, 0,
+    GET_LONG, REQUIRED_ARG, MI_KEY_BLOCK_LENGTH, MI_MIN_KEY_BLOCK_LENGTH,
+    MI_MAX_KEY_BLOCK_LENGTH, 0, MI_MIN_KEY_BLOCK_LENGTH, 0},
   { "myisam_block_size", OPT_MYISAM_BLOCK_SIZE,  "",
     (gptr*) &opt_myisam_block_size, (gptr*) &opt_myisam_block_size, 0,
     GET_LONG, REQUIRED_ARG, MI_KEY_BLOCK_LENGTH, MI_MIN_KEY_BLOCK_LENGTH,
@@ -1017,7 +1024,8 @@ static int myisamchk(MI_CHECK *param, my_string filename)
 	  !(param->testflag & (T_FAST | T_FORCE_CREATE)))
       {
 	if (param->testflag & (T_EXTEND | T_MEDIUM))
-	  VOID(init_key_cache(param->use_buffers));
+	  VOID(init_key_cache(dflt_keycache,opt_key_cache_block_size,
+                              param->use_buffers,&dflt_key_cache_var));
 	VOID(init_io_cache(&param->read_cache,datafile,
 			   (uint) param->read_buffer_length,
 			   READ_CACHE,
@@ -1439,7 +1447,8 @@ static int mi_sort_records(MI_CHECK *param,
   if (share->state.key_root[sort_key] == HA_OFFSET_ERROR)
     DBUG_RETURN(0);				/* Nothing to do */
 
-  init_key_cache(param->use_buffers);
+  init_key_cache(dflt_keycache,opt_key_cache_block_size,param->use_buffers,
+                 &dflt_key_cache_var);
   if (init_io_cache(&info->rec_cache,-1,(uint) param->write_buffer_length,
 		   WRITE_CACHE,share->pack.header_length,1,
 		   MYF(MY_WME | MY_WAIT_IF_FULL)))
diff --git a/myisam/myisamdef.h b/myisam/myisamdef.h
index 83e28a42797..9ed0e3ca3a2 100644
--- a/myisam/myisamdef.h
+++ b/myisam/myisamdef.h
@@ -166,6 +166,8 @@ typedef struct st_mi_isam_share {	/* Shared between opens */
   char  *data_file_name,		/* Resolved path names from symlinks */
         *index_file_name;
   byte *file_map;			/* mem-map of file if possible */
+  KEY_CACHE_HANDLE *keycache;           /* ref to the current key cache */
+  KEY_CACHE_HANDLE *reg_keycache;       /* ref to the registered key cache */
   MI_DECODE_TREE *decode_trees;
   uint16 *decode_tables;
   int (*read_record)(struct st_myisam_info*, my_off_t, byte*);
@@ -546,11 +548,12 @@ extern int _mi_search_next(MI_INFO *info,MI_KEYDEF *keyinfo,uchar *key,
 extern int _mi_search_first(MI_INFO *info,MI_KEYDEF *keyinfo,my_off_t pos);
 extern int _mi_search_last(MI_INFO *info,MI_KEYDEF *keyinfo,my_off_t pos);
 extern uchar *_mi_fetch_keypage(MI_INFO *info,MI_KEYDEF *keyinfo,my_off_t page,
-				uchar *buff,int return_buffer);
+				int level,uchar *buff,int return_buffer);
 extern int _mi_write_keypage(MI_INFO *info,MI_KEYDEF *keyinfo,my_off_t page,
-			     uchar *buff);
-extern int _mi_dispose(MI_INFO *info,MI_KEYDEF *keyinfo,my_off_t pos);
-extern my_off_t _mi_new(MI_INFO *info,MI_KEYDEF *keyinfo);
+			     int level, uchar *buff);
+extern int _mi_dispose(MI_INFO *info,MI_KEYDEF *keyinfo,my_off_t pos,
+                      int level);
+extern my_off_t _mi_new(MI_INFO *info,MI_KEYDEF *keyinfo,int level);
 extern uint _mi_make_key(MI_INFO *info,uint keynr,uchar *key,
 			 const byte *record,my_off_t filepos);
 extern uint _mi_pack_key(MI_INFO *info,uint keynr,uchar *key,uchar *old,
diff --git a/myisam/myisamlog.c b/myisam/myisamlog.c
index 4bb7cc55d30..5bca25dd439 100644
--- a/myisam/myisamlog.c
+++ b/myisam/myisamlog.c
@@ -333,7 +333,8 @@ static int examine_log(my_string file_name, char **table_names)
   bzero((gptr) com_count,sizeof(com_count));
   init_tree(&tree,0,0,sizeof(file_info),(qsort_cmp2) file_info_compare,1,
 	    (tree_element_free) file_info_free, NULL);
-  VOID(init_key_cache(KEY_CACHE_SIZE));
+  VOID(init_key_cache(dflt_keycache,KEY_CACHE_BLOCK_SIZE,KEY_CACHE_SIZE,
+                      &dflt_key_cache_var));
 
   files_open=0; access_time=0;
   while (access_time++ != number_of_commands &&
@@ -639,7 +640,7 @@ static int examine_log(my_string file_name, char **table_names)
       goto end;
     }
   }
-  end_key_cache();
+  end_key_cache(dflt_keycache,1);
   delete_tree(&tree);
   VOID(end_io_cache(&cache));
   VOID(my_close(file,MYF(0)));
@@ -659,7 +660,7 @@ static int examine_log(my_string file_name, char **table_names)
 	       llstr(isamlog_filepos,llbuff)));
   fflush(stderr);
  end:
-  end_key_cache();
+  end_key_cache(dflt_keycache,1);
   delete_tree(&tree);
   VOID(end_io_cache(&cache));
   VOID(my_close(file,MYF(0)));
diff --git a/myisam/rt_index.c b/myisam/rt_index.c
index f02d6121eb5..8b877d2e65c 100644
--- a/myisam/rt_index.c
+++ b/myisam/rt_index.c
@@ -60,7 +60,7 @@ static int rtree_find_req(MI_INFO *info, MI_KEYDEF *keyinfo, uint search_flag, u
     my_errno = HA_ERR_OUT_OF_MEM;
     return -1;
   }
-  if (!_mi_fetch_keypage(info, keyinfo, page, page_buf, 0))
+  if (!_mi_fetch_keypage(info, keyinfo, page, DFLT_INIT_HITS, page_buf, 0))
     goto err1;
   nod_flag = mi_test_if_nod(page_buf);
 
@@ -257,7 +257,7 @@ static int rtree_get_req(MI_INFO *info, MI_KEYDEF *keyinfo, uint key_length,
   
   if (!(page_buf = (uchar*)my_alloca((uint)keyinfo->block_length)))
     return -1;
-  if (!_mi_fetch_keypage(info, keyinfo, page, page_buf, 0))
+  if (!_mi_fetch_keypage(info, keyinfo, page, DFLT_INIT_HITS, page_buf, 0))
     goto err1;
   nod_flag = mi_test_if_nod(page_buf);
 
@@ -429,7 +429,7 @@ static int rtree_insert_req(MI_INFO *info, MI_KEYDEF *keyinfo, uchar *key,
     my_errno = HA_ERR_OUT_OF_MEM;
     return -1;
   }
-  if (!_mi_fetch_keypage(info, keyinfo, page, page_buf, 0))
+  if (!_mi_fetch_keypage(info, keyinfo, page, DFLT_INIT_HITS, page_buf, 0))
     goto err1;
   nod_flag = mi_test_if_nod(page_buf);
 
@@ -445,7 +445,7 @@ static int rtree_insert_req(MI_INFO *info, MI_KEYDEF *keyinfo, uchar *key,
       case 0: /* child was not split */
       {
         rtree_combine_rect(keyinfo->seg, k, key, k, key_length);
-        if (_mi_write_keypage(info, keyinfo, page, page_buf))
+        if (_mi_write_keypage(info, keyinfo, page, DFLT_INIT_HITS, page_buf))
           goto err1;
         goto ok;
       }
@@ -462,7 +462,7 @@ static int rtree_insert_req(MI_INFO *info, MI_KEYDEF *keyinfo, uchar *key,
           goto err1;
         res = rtree_add_key(info, keyinfo, new_key, key_length, 
                            page_buf, new_page);
-        if (_mi_write_keypage(info, keyinfo, page, page_buf))
+        if (_mi_write_keypage(info, keyinfo, page, DFLT_INIT_HITS, page_buf))
           goto err1;
         goto ok;
       }
@@ -476,7 +476,7 @@ static int rtree_insert_req(MI_INFO *info, MI_KEYDEF *keyinfo, uchar *key,
   else
   { 
     res = rtree_add_key(info, keyinfo, key, key_length, page_buf, new_page);
-    if (_mi_write_keypage(info, keyinfo, page, page_buf))
+    if (_mi_write_keypage(info, keyinfo, page, DFLT_INIT_HITS, page_buf))
       goto err1;
     goto ok;
   }
@@ -509,12 +509,12 @@ static int rtree_insert_level(MI_INFO *info, uint keynr, uchar *key,
   {
     int res;
 
-    if ((old_root = _mi_new(info, keyinfo)) == HA_OFFSET_ERROR)
+    if ((old_root = _mi_new(info, keyinfo, DFLT_INIT_HITS)) == HA_OFFSET_ERROR)
       return -1;
     info->buff_used = 1;
     mi_putint(info->buff, 2, 0);
     res = rtree_add_key(info, keyinfo, key, key_length, info->buff, NULL);
-    if (_mi_write_keypage(info, keyinfo, old_root, info->buff))
+    if (_mi_write_keypage(info, keyinfo, old_root, DFLT_INIT_HITS, info->buff))
       return 1;
     info->s->state.key_root[keynr] = old_root;
     return res;
@@ -542,7 +542,8 @@ static int rtree_insert_level(MI_INFO *info, uint keynr, uchar *key,
       }
 
       mi_putint(new_root_buf, 2, nod_flag);
-      if ((new_root = _mi_new(info, keyinfo)) == HA_OFFSET_ERROR)
+      if ((new_root = _mi_new(info, keyinfo, DFLT_INIT_HITS)) ==
+                                                             HA_OFFSET_ERROR)
         goto err1;
 
       new_key = new_root_buf + keyinfo->block_length + nod_flag;
@@ -559,7 +560,8 @@ static int rtree_insert_level(MI_INFO *info, uint keynr, uchar *key,
       if (rtree_add_key(info, keyinfo, new_key, key_length, new_root_buf, NULL) 
           == -1)
         goto err1;
-      if (_mi_write_keypage(info, keyinfo, new_root, new_root_buf))
+      if (_mi_write_keypage(info, keyinfo, new_root,
+                            DFLT_INIT_HITS, new_root_buf))
         goto err1;
       info->s->state.key_root[keynr] = new_root;
 
@@ -636,7 +638,7 @@ static int rtree_delete_req(MI_INFO *info, MI_KEYDEF *keyinfo, uchar *key,
     my_errno = HA_ERR_OUT_OF_MEM;
     return -1;
   }
-  if (!_mi_fetch_keypage(info, keyinfo, page, page_buf, 0))
+  if (!_mi_fetch_keypage(info, keyinfo, page, DFLT_INIT_HITS, page_buf, 0))
     goto err1;
   nod_flag = mi_test_if_nod(page_buf);
 
@@ -662,7 +664,8 @@ static int rtree_delete_req(MI_INFO *info, MI_KEYDEF *keyinfo, uchar *key,
               if (rtree_set_key_mbr(info, keyinfo, k, key_length, 
                                   _mi_kpos(nod_flag, k)))
                 goto err1;
-              if (_mi_write_keypage(info, keyinfo, page, page_buf))
+              if (_mi_write_keypage(info, keyinfo, page,
+                                    DFLT_INIT_HITS, page_buf))
                 goto err1;
             }
             else
@@ -672,7 +675,8 @@ static int rtree_delete_req(MI_INFO *info, MI_KEYDEF *keyinfo, uchar *key,
                                            level + 1))
                 goto err1;
               rtree_delete_key(info, page_buf, k, key_length, nod_flag);
-              if (_mi_write_keypage(info, keyinfo, page, page_buf))
+              if (_mi_write_keypage(info, keyinfo, page,
+                                    DFLT_INIT_HITS, page_buf))
                 goto err1;
               *page_size = mi_getint(page_buf);
             }
@@ -686,7 +690,8 @@ static int rtree_delete_req(MI_INFO *info, MI_KEYDEF *keyinfo, uchar *key,
           case 2: /* vacuous case: last key in the leaf */
           {
             rtree_delete_key(info, page_buf, k, key_length, nod_flag);
-            if (_mi_write_keypage(info, keyinfo, page, page_buf))
+            if (_mi_write_keypage(info, keyinfo, page,
+                                  DFLT_INIT_HITS, page_buf))
               goto err1;
             *page_size = mi_getint(page_buf);
             res = 0;
@@ -711,13 +716,13 @@ static int rtree_delete_req(MI_INFO *info, MI_KEYDEF *keyinfo, uchar *key,
         {
           /* last key in the leaf */
           res = 2;
-          if (_mi_dispose(info, keyinfo, page))
+          if (_mi_dispose(info, keyinfo, page, DFLT_INIT_HITS))
             goto err1;
         }
         else
         {
           res = 0;
-          if (_mi_write_keypage(info, keyinfo, page, page_buf))
+          if (_mi_write_keypage(info, keyinfo, page, DFLT_INIT_HITS, page_buf))
             goto err1;
         }
         goto ok;
@@ -783,7 +788,7 @@ int rtree_delete(MI_INFO *info, uint keynr, uchar *key, uint key_length)
           goto err1;
         }
         if (!_mi_fetch_keypage(info, keyinfo, ReinsertList.pages[i].offs, 
-                               page_buf, 0))
+                               DFLT_INIT_HITS, page_buf, 0))
           goto err1;
         nod_flag = mi_test_if_nod(page_buf);
         k = rt_PAGE_FIRST_KEY(page_buf, nod_flag);
@@ -798,7 +803,8 @@ int rtree_delete(MI_INFO *info, uint keynr, uchar *key, uint key_length)
           }
         }
         my_afree((byte*)page_buf);
-        if (_mi_dispose(info, keyinfo, ReinsertList.pages[i].offs))
+        if (_mi_dispose(info, keyinfo, ReinsertList.pages[i].offs,
+            DFLT_INIT_HITS))
           goto err1;
       }
       if (ReinsertList.pages)
@@ -807,7 +813,8 @@ int rtree_delete(MI_INFO *info, uint keynr, uchar *key, uint key_length)
       /* check for redundant root (not leaf, 1 child) and eliminate */
       if ((old_root = info->s->state.key_root[keynr]) == HA_OFFSET_ERROR)
         goto err1;
-      if (!_mi_fetch_keypage(info, keyinfo, old_root, info->buff, 0))
+      if (!_mi_fetch_keypage(info, keyinfo, old_root, DFLT_INIT_HITS, 
+                             info->buff, 0))
         goto err1;
       nod_flag = mi_test_if_nod(info->buff);
       page_size = mi_getint(info->buff);
@@ -816,7 +823,7 @@ int rtree_delete(MI_INFO *info, uint keynr, uchar *key, uint key_length)
       {
         my_off_t new_root = _mi_kpos(nod_flag, 
                                      rt_PAGE_FIRST_KEY(info->buff, nod_flag));
-        if (_mi_dispose(info, keyinfo, old_root))
+        if (_mi_dispose(info, keyinfo, old_root, DFLT_INIT_HITS))
           goto err1;
         info->s->state.key_root[keynr] = new_root;
       }
@@ -863,7 +870,7 @@ ha_rows rtree_estimate(MI_INFO *info, uint keynr, uchar *key,
     return HA_POS_ERROR;
   if (!(page_buf = (uchar*)my_alloca((uint)keyinfo->block_length)))
     return HA_POS_ERROR;
-  if (!_mi_fetch_keypage(info, keyinfo, root, page_buf, 0))
+  if (!_mi_fetch_keypage(info, keyinfo, root, DFLT_INIT_HITS, page_buf, 0))
     goto err1;
   nod_flag = mi_test_if_nod(page_buf);
 
diff --git a/myisam/rt_key.c b/myisam/rt_key.c
index dfabf7624d2..f18d13af8d8 100644
--- a/myisam/rt_key.c
+++ b/myisam/rt_key.c
@@ -88,7 +88,8 @@ int rtree_delete_key(MI_INFO *info, uchar *page_buf, uchar *key,
 int rtree_set_key_mbr(MI_INFO *info, MI_KEYDEF *keyinfo, uchar *key, 
 		      uint key_length, my_off_t child_page)
 {
-  if (!_mi_fetch_keypage(info, keyinfo, child_page, info->buff, 0))
+  if (!_mi_fetch_keypage(info, keyinfo, child_page,
+                         DFLT_INIT_HITS, info->buff, 0))
     return -1;
 
   return rtree_page_mbr(info, keyinfo->seg, info->buff, key, key_length);
diff --git a/myisam/rt_split.c b/myisam/rt_split.c
index 72a3c4887ab..41d6f8f8ccd 100644
--- a/myisam/rt_split.c
+++ b/myisam/rt_split.c
@@ -332,10 +332,12 @@ int rtree_split_page(MI_INFO *info, MI_KEYDEF *keyinfo, uchar *page, uchar *key,
   mi_putint(page, 2 + n1 * full_length, nod_flag);
   mi_putint(new_page, 2 + n2 * full_length, nod_flag);
 
-  if ((*new_page_offs= _mi_new(info, keyinfo)) == HA_OFFSET_ERROR)
+  if ((*new_page_offs= _mi_new(info, keyinfo, DFLT_INIT_HITS)) == 
+                                                               HA_OFFSET_ERROR)
     err_code= -1;
   else
-    err_code= _mi_write_keypage(info, keyinfo, *new_page_offs, new_page);
+    err_code= _mi_write_keypage(info, keyinfo, *new_page_offs,
+                                DFLT_INIT_HITS, new_page);
 
   my_afree((byte*)new_page);