~tsarev/percona-server/5.5-processlist_rows_stats-sporadic_fails-fix

diff -ruN a/include/heap.h b/include/heap.h
--- a/include/heap.h	2011-04-11 13:44:02.000000000 +0300
+++ b/include/heap.h	2011-06-02 15:28:13.294917001 +0300
@@ -33,7 +33,17 @@
 #include "my_compare.h"
 #include "my_tree.h"
 
-	/* defines used by heap-funktions */
+/* Define index limits to be identical to MyISAM ones for compatibility. */
+
+#if MAX_INDEXES > HA_MAX_POSSIBLE_KEY
+#define HP_MAX_KEY                  HA_MAX_POSSIBLE_KEY /* Max allowed keys */
+#else
+#define HP_MAX_KEY                  MAX_INDEXES         /* Max allowed keys */
+#endif
+
+#define HP_MAX_KEY_LENGTH           1000            /* Max length in bytes */
+
+/* defines used by heap-funktions */
 
 #define HP_MAX_LEVELS	4		/* 128^5 records is enough */
 #define HP_PTRS_IN_NOD	128
@@ -129,22 +139,58 @@
   uint (*get_key_length)(struct st_hp_keydef *keydef, const uchar *key);
 } HP_KEYDEF;
 
-typedef struct st_heap_share
+typedef struct st_heap_columndef		/* column information */
+{
+  int16  type;	  			/* en_fieldtype */
+  uint32 length;		  	/* length of field */
+  uint32 offset;		  	/* Offset to position in row */
+  uint8  null_bit;			/* If column may be 0 */
+  uint16 null_pos;			/* position for null marker */
+  uint8  length_bytes;			/* length of the size, 1 o 2 bytes */
+} HP_COLUMNDEF;
+
+typedef struct st_heap_dataspace   /* control data for data space */
 {
   HP_BLOCK block;
+  /* Total chunks ever allocated in this dataspace */
+  uint chunk_count;
+  uint del_chunk_count;         /* Deleted chunks count */
+  uchar *del_link;              /* Link to last deleted chunk */
+  uint chunk_length;            /* Total length of one chunk */
+  /* Length of payload that will be placed into one chunk */
+  uint chunk_dataspace_length;
+  /* Offset of the status flag relative to the chunk start */
+  uint offset_status;
+  /* Offset of the linking pointer relative to the chunk start */
+  uint offset_link;
+  /* Test whether records have variable size and so "next" pointer */
+  uint is_variable_size;
+  /* Total size allocated within this data space */
+  ulonglong total_data_length;
+} HP_DATASPACE;
+
+typedef struct st_heap_share
+{
   HP_KEYDEF  *keydef;
+  HP_COLUMNDEF *column_defs;
+  /* Describes "block", which contains actual records */
+  HP_DATASPACE recordspace;
   ulong min_records,max_records;	/* Params to open */
-  ulonglong data_length,index_length,max_table_size;
+  ulonglong index_length, max_table_size;
   uint key_stat_version;                /* version to indicate insert/delete */
-  uint records;				/* records */
-  uint blength;				/* records rounded up to 2^n */
-  uint deleted;				/* Deleted records in database */
-  uint reclength;			/* Length of one record */
+  uint records;			/* Actual record (row) count */
+  uint blength;			/* used_chunk_count rounded up to 2^n */
+  /*
+    Length of record's fixed part, which contains keys and always fits into the
+    first chunk.
+  */
+  uint fixed_data_length;
+  uint fixed_column_count;  /* Number of columns stored in fixed_data_length */
   uint changed;
   uint keys,max_key_length;
+  uint column_count;
   uint currently_disabled_keys;    /* saved value from "keys" when disabled */
   uint open_count;
-  uchar *del_link;			/* Link to next block with del. rec */
   char * name;			/* Name of "memory-file" */
   THR_LOCK lock;
   mysql_mutex_t intern_lock;            /* Locking for use with _locking */
@@ -153,6 +199,7 @@
   uint auto_key;
   uint auto_key_type;			/* real type of the auto key segment */
   ulonglong auto_increment;
+  uint blobs;  /* Number of blobs in table */
 } HP_SHARE;
 
 struct st_hp_hash_info;
@@ -162,7 +209,7 @@
   HP_SHARE *s;
   uchar *current_ptr;
   struct st_hp_hash_info *current_hash_ptr;
-  ulong current_record,next_block;
+  ulong current_record;
   int lastinx,errkey;
   int  mode;				/* Mode of file (READONLY..) */
   uint opt_flag,update;
@@ -175,6 +222,9 @@
   my_bool implicit_emptied;
   THR_LOCK_DATA lock;
   LIST open_list;
+  uchar *blob_buffer;  /* Temporary buffer used to return BLOB values */
+  uint blob_size;      /* Current blob_buffer size */
+  uint blob_offset;    /* Current offset in blob_buffer */
 } HP_INFO;
 
 
@@ -196,6 +246,14 @@
     open_count to 1. Is only looked at if not internal_table.
   */
   my_bool pin_share;
+  uint columns;
+  HP_COLUMNDEF *columndef;
+  uint fixed_key_fieldnr;
+  uint fixed_data_size;
+  uint keys_memory_size;
+  uint max_chunk_size;
+  uint is_dynamic;
+  uint blobs;
 } HP_CREATE_INFO;
 
 	/* Prototypes for heap-functions */
@@ -212,9 +270,8 @@
 extern int heap_scan(register HP_INFO *info, uchar *record);
 extern int heap_delete(HP_INFO *info,const uchar *buff);
 extern int heap_info(HP_INFO *info,HEAPINFO *x,int flag);
-extern int heap_create(const char *name,
-                       HP_CREATE_INFO *create_info, HP_SHARE **share,
-                       my_bool *created_new_share);
+extern int heap_create(const char *name, HP_CREATE_INFO *create_info,
+                       HP_SHARE **res, my_bool *created_new_share);
 extern int heap_delete_table(const char *name);
 extern void heap_drop_table(HP_INFO *info);
 extern int heap_extra(HP_INFO *info,enum ha_extra_function function);
diff -ruN a/mysql-test/r/create.result b/mysql-test/r/create.result
--- a/mysql-test/r/create.result	2011-06-02 11:38:04.000000000 +0300
+++ b/mysql-test/r/create.result	2011-06-02 15:56:29.224917005 +0300
@@ -33,10 +33,7 @@
 create table t1 (b char(0) not null, index(b));
 ERROR 42000: The used storage engine can't index column 'b'
 create table t1 (a int not null,b text) engine=heap;
-ERROR 42000: The used table type doesn't support BLOB/TEXT columns
 drop table if exists t1;
-Warnings:
-Note	1051	Unknown table 't1'
 create table t1 (ordid int(8) not null auto_increment, ord  varchar(50) not null, primary key (ord,ordid)) engine=heap;
 ERROR 42000: Incorrect table definition; there can be only one auto column and it must be defined as a key
 create table not_existing_database.test (a int);
diff -ruN a/mysql-test/r/ctype_utf8mb4_heap.result b/mysql-test/r/ctype_utf8mb4_heap.result
--- a/mysql-test/r/ctype_utf8mb4_heap.result	2011-04-11 13:44:02.000000000 +0300
+++ b/mysql-test/r/ctype_utf8mb4_heap.result	2011-06-02 15:31:07.794917003 +0300
@@ -1124,6 +1124,8 @@
 a varchar(255) NOT NULL default '',
 KEY a (a)
 ) ENGINE=heap DEFAULT CHARSET=utf8mb4 COLLATE utf8mb4_general_ci;
+Warnings:
+Warning	1071	Specified key was too long; max key length is 1000 bytes
 insert into t1 values (_utf8mb4 0xe880bd);
 insert into t1 values (_utf8mb4 0x5b);
 select hex(a) from t1;
@@ -1162,6 +1164,8 @@
 Warnings:
 Note	1051	Unknown table 't1'
 CREATE TABLE t1(a VARCHAR(255), KEY(a)) ENGINE=heap DEFAULT CHARSET=utf8mb4;
+Warnings:
+Warning	1071	Specified key was too long; max key length is 1000 bytes
 INSERT INTO t1 VALUES('uuABCDEFGHIGKLMNOPRSTUVWXYZ̈bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb');
 INSERT INTO t1 VALUES('uu');
 check table t1;
diff -ruN a/mysql-test/t/create.test b/mysql-test/t/create.test
--- a/mysql-test/t/create.test	2011-04-11 13:44:01.000000000 +0300
+++ b/mysql-test/t/create.test	2011-06-02 15:32:49.614917004 +0300
@@ -33,7 +33,7 @@
 drop table if exists t1,t2;
 --error 1167
 create table t1 (b char(0) not null, index(b));
---error 1163
+# BLOB/TEXT fields are now supported by HEAP
 create table t1 (a int not null,b text) engine=heap;
 drop table if exists t1;
 
diff -ruN a/storage/heap/CMakeLists.txt b/storage/heap/CMakeLists.txt
--- a/storage/heap/CMakeLists.txt	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/CMakeLists.txt	2011-06-02 15:37:43.744917005 +0300
@@ -20,6 +20,7 @@
 				ha_heap.cc
 				hp_delete.c hp_extra.c hp_hash.c hp_info.c hp_open.c hp_panic.c
 				hp_rename.c hp_rfirst.c hp_rkey.c hp_rlast.c hp_rnext.c hp_rprev.c
+				hp_dspace.c hp_record.c
 				hp_rrnd.c hp_rsame.c hp_scan.c hp_static.c hp_update.c hp_write.c)
 
 MYSQL_ADD_PLUGIN(heap ${HEAP_SOURCES} STORAGE_ENGINE MANDATORY RECOMPILE_FOR_EMBEDDED)
diff -ruN a/storage/heap/_check.c b/storage/heap/_check.c
--- a/storage/heap/_check.c	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/_check.c	2011-06-02 15:37:43.744917005 +0300
@@ -43,7 +43,7 @@
 {
   int error;
   uint key;
-  ulong records=0, deleted=0, pos, next_block;
+  ulong records= 0, deleted= 0, chunk_count= 0, pos, next_block;
   HP_SHARE *share=info->s;
   HP_INFO save_info= *info;			/* Needed because scan_init */
   DBUG_ENTER("heap_check_heap");
@@ -64,31 +64,55 @@
   {
     if (pos < next_block)
     {
-      info->current_ptr+= share->block.recbuffer;
+      info->current_ptr+= share->recordspace.block.recbuffer;
     }
     else
     {
-      next_block+= share->block.records_in_block;
-      if (next_block >= share->records+share->deleted)
+      next_block+= share->recordspace.block.records_in_block;
+      if (next_block >= share->recordspace.chunk_count)
       {
-	next_block= share->records+share->deleted;
-	if (pos >= next_block)
-	  break;				/* End of file */
+        next_block= share->recordspace.chunk_count;
+        if (pos >= next_block)
+          break;				/* End of file */
       }
     }
     hp_find_record(info,pos);
 
-    if (!info->current_ptr[share->reclength])
+    switch (get_chunk_status(&share->recordspace, info->current_ptr)) {
+    case CHUNK_STATUS_DELETED:
       deleted++;
-    else
+      chunk_count++;
+      break;
+    case CHUNK_STATUS_ACTIVE:
       records++;
+        chunk_count++;
+        break;
+    case CHUNK_STATUS_LINKED:
+      chunk_count++;
+      break;
+    default:
+      DBUG_PRINT("error",
+                 ("Unknown record status: Record: 0x%lx  Status %lu",
+                  (long) info->current_ptr,
+                  (ulong) get_chunk_status(&share->recordspace,
+                                           info->current_ptr)));
+        error|= 1;
+        break;
+    }
   }
 
-  if (records != share->records || deleted != share->deleted)
-  {
-    DBUG_PRINT("error",("Found rows: %lu (%lu)  deleted %lu (%lu)",
-			records, (ulong) share->records,
-                        deleted, (ulong) share->deleted));
+  /* TODO: verify linked chunks (no orphans, no cycles, no bad links) */
+
+  if (records != share->records ||
+      chunk_count != share->recordspace.chunk_count ||
+      deleted != share->recordspace.del_chunk_count)
+  {
+    DBUG_PRINT("error",
+               ("Found rows: %lu (%lu) total chunks %lu (%lu) deleted chunks "
+                "%lu (%lu)",
+                records, (ulong) share->records,
+                chunk_count, (ulong) share->recordspace.chunk_count,
+                deleted, (ulong) share->recordspace.del_chunk_count));
     error= 1;
   }
   *info= save_info;
@@ -177,7 +201,7 @@
     do
     {
       memcpy(&recpos, key + (*keydef->get_key_length)(keydef,key), sizeof(uchar*));
-      key_length= hp_rb_make_key(keydef, info->recbuf, recpos, 0);
+      key_length= hp_rb_make_key(keydef, info->recbuf, recpos, 0, TRUE);
       if (ha_key_cmp(keydef->seg, (uchar*) info->recbuf, (uchar*) key,
 		     key_length, SEARCH_FIND | SEARCH_SAME, not_used))
       {
diff -ruN a/storage/heap/_rectest.c b/storage/heap/_rectest.c
--- a/storage/heap/_rectest.c	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/_rectest.c	2011-06-02 15:38:02.774917002 +0300
@@ -22,7 +22,9 @@
 {
   DBUG_ENTER("hp_rectest");
 
-  if (memcmp(info->current_ptr,old,(size_t) info->s->reclength))
+  if (hp_process_record_data_to_chunkset(info->s, old,
+                                         info->current_ptr,
+                                         1))
   {
     DBUG_RETURN((my_errno=HA_ERR_RECORD_CHANGED)); /* Record have changed */
   }
diff -ruN a/storage/heap/ha_heap.cc b/storage/heap/ha_heap.cc
--- a/storage/heap/ha_heap.cc	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/ha_heap.cc	2011-06-02 15:37:43.744917005 +0300
@@ -113,6 +113,7 @@
 
     rc= heap_create(name, &create_info, &internal_share, &created_new_share);
     my_free(create_info.keydef);
+    my_free(create_info.columndef);
     if (rc)
       goto end;
 
@@ -194,6 +195,12 @@
   {
     if (table->key_info[i].algorithm == HA_KEY_ALG_BTREE)
       btree_keys.set_bit(i);
+    /*
+      Reset per-key block size specification so they are not shown
+      in SHOW CREATE TABLE.
+    */
+    table->key_info[i].block_size= 0;
+    table->key_info[i].flags&= ~HA_USES_BLOCK_SIZE;
   }
 }
 
@@ -427,6 +434,13 @@
   return 0;
 }
 
+enum row_type ha_heap::get_row_type() const
+{
+  if (file->s->recordspace.is_variable_size)
+    return ROW_TYPE_DYNAMIC;
+
+  return ROW_TYPE_FIXED;
+}
 
 int ha_heap::extra(enum ha_extra_function operation)
 {
@@ -644,23 +658,70 @@
 heap_prepare_hp_create_info(TABLE *table_arg, bool internal_table,
                             HP_CREATE_INFO *hp_create_info)
 {
-  uint key, parts, mem_per_row= 0, keys= table_arg->s->keys;
+  uint key, parts, mem_per_row_keys= 0, keys= table_arg->s->keys;
   uint auto_key= 0, auto_key_type= 0;
-  ha_rows max_rows;
+  uint fixed_key_fieldnr = 0, fixed_data_size = 0, next_field_pos = 0;
+  uint column_idx, column_count= table_arg->s->fields;
+  HP_COLUMNDEF *columndef;
   HP_KEYDEF *keydef;
   HA_KEYSEG *seg;
   TABLE_SHARE *share= table_arg->s;
   bool found_real_auto_increment= 0;
+  uint blobs= 0;
 
   bzero(hp_create_info, sizeof(*hp_create_info));
 
+  if (!(columndef= (HP_COLUMNDEF*) my_malloc(column_count *
+                                             sizeof(HP_COLUMNDEF),
+                                             MYF(MY_WME))))
+    return my_errno;
+
+  for (column_idx= 0; column_idx < column_count; column_idx++)
+  {
+    Field* field= *(table_arg->field + column_idx);
+    HP_COLUMNDEF* column= columndef + column_idx;
+    column->type= (uint16) field->type();
+    column->length= field->pack_length();
+    column->offset= field->offset(table_arg->record[0]);
+
+    if (field->null_bit)
+    {
+      column->null_bit= field->null_bit;
+      column->null_pos= (uint) (field->null_ptr -
+                                (uchar*) table_arg->record[0]);
+    }
+    else
+    {
+      column->null_bit= 0;
+      column->null_pos= 0;
+    }
+
+    if (field->type() == MYSQL_TYPE_VARCHAR)
+    {
+      column->length_bytes= (uint8) (((Field_varstring *) field)->length_bytes);
+    }
+    else if (field->type() == MYSQL_TYPE_BLOB)
+    {
+      blobs++;
+      column->length_bytes= (uint8)
+        (((Field_blob *) field)->pack_length_no_ptr());
+    }
+    else
+    {
+      column->length_bytes= 0;
+    }
+  }
+
   for (key= parts= 0; key < keys; key++)
     parts+= table_arg->key_info[key].key_parts;
 
   if (!(keydef= (HP_KEYDEF*) my_malloc(keys * sizeof(HP_KEYDEF) +
 				       parts * sizeof(HA_KEYSEG),
 				       MYF(MY_WME))))
+  {
+    my_free((uchar *) columndef);
     return my_errno;
+  }
   seg= reinterpret_cast<HA_KEYSEG*>(keydef + keys);
   for (key= 0; key < keys; key++)
   {
@@ -676,11 +737,11 @@
     case HA_KEY_ALG_UNDEF:
     case HA_KEY_ALG_HASH:
       keydef[key].algorithm= HA_KEY_ALG_HASH;
-      mem_per_row+= sizeof(char*) * 2; // = sizeof(HASH_INFO)
+      mem_per_row_keys+= sizeof(char*) * 2; // = sizeof(HASH_INFO)
       break;
     case HA_KEY_ALG_BTREE:
       keydef[key].algorithm= HA_KEY_ALG_BTREE;
-      mem_per_row+=sizeof(TREE_ELEMENT)+pos->key_length+sizeof(char*);
+      mem_per_row_keys+=sizeof(TREE_ELEMENT)+pos->key_length+sizeof(char*);
       break;
     default:
       DBUG_ASSERT(0); // cannot happen
@@ -705,6 +766,16 @@
       seg->length=  (uint) key_part->length;
       seg->flag=    key_part->key_part_flag;
 
+      next_field_pos= seg->start;
+      if (field->type() == MYSQL_TYPE_VARCHAR)
+      {
+        Field *orig_field= *(table_arg->field + key_part->field->field_index);
+        next_field_pos+= orig_field->pack_length();
+      }
+      else
+      {
+        next_field_pos+= seg->length;
+      }
       if (field->flags & (ENUM_FLAG | SET_FLAG))
         seg->charset= &my_charset_bin;
       else
@@ -730,9 +801,75 @@
         auto_key= key+ 1;
 	auto_key_type= field->key_type();
       }
+
+      switch (seg->type) {
+      case HA_KEYTYPE_SHORT_INT:
+      case HA_KEYTYPE_LONG_INT:
+      case HA_KEYTYPE_FLOAT:
+      case HA_KEYTYPE_DOUBLE:
+      case HA_KEYTYPE_USHORT_INT:
+      case HA_KEYTYPE_ULONG_INT:
+      case HA_KEYTYPE_LONGLONG:
+      case HA_KEYTYPE_ULONGLONG:
+      case HA_KEYTYPE_INT24:
+      case HA_KEYTYPE_UINT24:
+      case HA_KEYTYPE_INT8:
+        seg->flag|= HA_SWAP_KEY;
+        break;
+      case HA_KEYTYPE_VARBINARY1:
+        /* Case-insensitiveness is handled in coll->hash_sort */
+        seg->type= HA_KEYTYPE_VARTEXT1;
+        /* fall through */
+      case HA_KEYTYPE_VARTEXT1:
+        keydef[key].flag|= HA_VAR_LENGTH_KEY;
+        /* Save number of bytes used to store length */
+        if (seg->flag & HA_BLOB_PART)
+          seg->bit_start= field->pack_length() - share->blob_ptr_size;
+        else
+          seg->bit_start= 1;
+        break;
+      case HA_KEYTYPE_VARBINARY2:
+        /* Case-insensitiveness is handled in coll->hash_sort */
+        /* fall_through */
+      case HA_KEYTYPE_VARTEXT2:
+        keydef[key].flag|= HA_VAR_LENGTH_KEY;
+        /* Save number of bytes used to store length */
+        if (seg->flag & HA_BLOB_PART)
+          seg->bit_start= field->pack_length() - share->blob_ptr_size;
+        else
+          seg->bit_start= 2;
+        /*
+          Make future comparison simpler by only having to check for
+          one type
+        */
+        seg->type= HA_KEYTYPE_VARTEXT1;
+        break;
+      default:
+        break;
+      }
+
+      if (next_field_pos > fixed_data_size)
+      {
+        fixed_data_size= next_field_pos;
+      }
+
+
+      if (field->field_index >= fixed_key_fieldnr)
+      {
+        /*
+          Do not use seg->fieldnr as it's not reliable in case of temp tables
+        */
+        fixed_key_fieldnr= field->field_index + 1;
+      }
     }
   }
-  mem_per_row+= MY_ALIGN(share->reclength + 1, sizeof(char*));
+
+  if (fixed_data_size < share->null_bytes)
+  {
+    /* Make sure to include null fields regardless of the presense of keys */
+    fixed_data_size = share->null_bytes;
+  }
+
   if (table_arg->found_next_number_field)
   {
     keydef[share->next_number_index].flag|= HA_AUTO_KEY;
@@ -743,16 +880,19 @@
   hp_create_info->max_table_size=current_thd->variables.max_heap_table_size;
   hp_create_info->with_auto_increment= found_real_auto_increment;
   hp_create_info->internal_table= internal_table;
-
-  max_rows= (ha_rows) (hp_create_info->max_table_size / mem_per_row);
-  if (share->max_rows && share->max_rows < max_rows)
-    max_rows= share->max_rows;
-
-  hp_create_info->max_records= (ulong) max_rows;
+  hp_create_info->max_chunk_size= share->key_block_size;
+  hp_create_info->is_dynamic= (share->row_type == ROW_TYPE_DYNAMIC);
+  hp_create_info->columns= column_count;
+  hp_create_info->columndef= columndef;
+  hp_create_info->fixed_key_fieldnr= fixed_key_fieldnr;
+  hp_create_info->fixed_data_size= fixed_data_size;
+  hp_create_info->max_records= (ulong) share->max_rows;
   hp_create_info->min_records= (ulong) share->min_rows;
   hp_create_info->keys= share->keys;
   hp_create_info->reclength= share->reclength;
+  hp_create_info->keys_memory_size= mem_per_row_keys;
   hp_create_info->keydef= keydef;
+  hp_create_info->blobs= blobs;
   return 0;
 }
 
@@ -772,6 +912,7 @@
 				  create_info->auto_increment_value - 1 : 0);
   error= heap_create(name, &hp_create_info, &internal_share, &created);
   my_free(hp_create_info.keydef);
+  my_free(hp_create_info.columndef);
   DBUG_ASSERT(file == 0);
   return (error);
 }
@@ -782,6 +923,13 @@
   table->file->info(HA_STATUS_AUTO);
   if (!(create_info->used_fields & HA_CREATE_USED_AUTO))
     create_info->auto_increment_value= stats.auto_increment_value;
+  if (!(create_info->used_fields & HA_CREATE_USED_KEY_BLOCK_SIZE))
+  {
+    if (file->s->recordspace.is_variable_size)
+      create_info->key_block_size= file->s->recordspace.chunk_length;
+    else
+      create_info->key_block_size= 0;
+  }
 }
 
 void ha_heap::get_auto_increment(ulonglong offset, ulonglong increment,
diff -ruN a/storage/heap/ha_heap.h b/storage/heap/ha_heap.h
--- a/storage/heap/ha_heap.h	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/ha_heap.h	2011-06-02 15:37:43.744917005 +0300
@@ -46,12 +46,11 @@
     return ((table_share->key_info[inx].algorithm == HA_KEY_ALG_BTREE) ?
             "BTREE" : "HASH");
   }
-  /* Rows also use a fixed-size format */
-  enum row_type get_row_type() const { return ROW_TYPE_FIXED; }
+  enum row_type get_row_type() const;
   const char **bas_ext() const;
   ulonglong table_flags() const
   {
-    return (HA_FAST_KEY_READ | HA_NO_BLOBS | HA_NULL_IN_KEY |
+    return (HA_FAST_KEY_READ | HA_NULL_IN_KEY |
             HA_BINLOG_ROW_CAPABLE | HA_BINLOG_STMT_CAPABLE |
             HA_REC_NOT_IN_SEQ | HA_CAN_INSERT_DELAYED | HA_NO_TRANSACTIONS |
             HA_HAS_RECORDS | HA_STATS_RECORDS_IS_EXACT);
@@ -63,8 +62,9 @@
             HA_ONLY_WHOLE_INDEX | HA_KEY_SCAN_NOT_ROR);
   }
   const key_map *keys_to_use_for_scanning() { return &btree_keys; }
-  uint max_supported_keys()          const { return MAX_KEY; }
-  uint max_supported_key_part_length() const { return MAX_KEY_LENGTH; }
+  uint max_supported_keys()          const { return HP_MAX_KEY; }
+  uint max_supported_key_length() const { return HP_MAX_KEY_LENGTH; }
+  uint max_supported_key_part_length() const { return HP_MAX_KEY_LENGTH; }
   double scan_time()
   { return (double) (stats.records+stats.deleted) / 20.0+10; }
   double read_time(uint index, uint ranges, ha_rows rows)
diff -ruN a/storage/heap/heapdef.h b/storage/heap/heapdef.h
--- a/storage/heap/heapdef.h	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/heapdef.h	2011-06-02 15:37:43.754916999 +0300
@@ -32,6 +32,13 @@
 #define HP_MIN_RECORDS_IN_BLOCK 16
 #define HP_MAX_RECORDS_IN_BLOCK 8192
 
+/* this chunk has been deleted and can be reused */
+#define CHUNK_STATUS_DELETED 0
+/* this chunk represents the first part of a live record */
+#define CHUNK_STATUS_ACTIVE  1
+/* this chunk is a continuation from another chunk (part of chunkset) */
+#define CHUNK_STATUS_LINKED  2
+
 	/* Some extern variables */
 
 extern LIST *heap_open_list,*heap_share_list;
@@ -42,7 +49,14 @@
 #define hp_find_hash(A,B) ((HASH_INFO*) hp_find_block((A),(B)))
 
 	/* Find pos for record and update it in info->current_ptr */
-#define hp_find_record(info,pos) (info)->current_ptr= hp_find_block(&(info)->s->block,pos)
+#define hp_find_record(info,pos) \
+  (info)->current_ptr= hp_find_block(&(info)->s->recordspace.block,pos)
+
+#define get_chunk_status(info,ptr) (ptr[(info)->offset_status])
+
+#define get_chunk_count(info,rec_length) \
+  ((rec_length + (info)->chunk_dataspace_length - 1) / \
+   (info)->chunk_dataspace_length)
 
 typedef struct st_hp_hash_info
 {
@@ -90,7 +104,7 @@
 		      const uchar *key);
 extern void hp_make_key(HP_KEYDEF *keydef,uchar *key,const uchar *rec);
 extern uint hp_rb_make_key(HP_KEYDEF *keydef, uchar *key,
-			   const uchar *rec, uchar *recpos);
+			   const uchar *rec, uchar *recpos, my_bool packed);
 extern uint hp_rb_key_length(HP_KEYDEF *keydef, const uchar *key);
 extern uint hp_rb_null_key_length(HP_KEYDEF *keydef, const uchar *key);
 extern uint hp_rb_var_key_length(HP_KEYDEF *keydef, const uchar *key);
@@ -100,6 +114,23 @@
 extern void hp_clear_keys(HP_SHARE *info);
 extern uint hp_rb_pack_key(HP_KEYDEF *keydef, uchar *key, const uchar *old,
                            key_part_map keypart_map);
+extern uint hp_calc_blob_length(uint length, const uchar *pos);
+
+/* Chunkset management (alloc/free/encode/decode) functions */
+extern uchar *hp_allocate_chunkset(HP_DATASPACE *info, uint chunk_count);
+extern int hp_reallocate_chunkset(HP_DATASPACE *info, uint chunk_count,
+                                  uchar *pos);
+extern void hp_free_chunks(HP_DATASPACE *info, uchar *pos);
+extern void hp_clear_dataspace(HP_DATASPACE *info);
+
+extern uint hp_get_encoded_data_length(HP_SHARE *info, const uchar *record,
+                                       uint *chunk_count);
+extern void hp_copy_record_data_to_chunkset(HP_SHARE *info, const uchar *record,
+                                            uchar *pos);
+extern int hp_extract_record(HP_INFO *info, uchar *record, const uchar *pos);
+extern uint hp_process_record_data_to_chunkset(HP_SHARE *info,
+                                               const uchar *record, uchar *pos,
+                                               uint is_compare);
 
 extern mysql_mutex_t THR_LOCK_heap;
 
diff -ruN a/storage/heap/hp_clear.c b/storage/heap/hp_clear.c
--- a/storage/heap/hp_clear.c	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/hp_clear.c	2011-06-02 15:37:43.754916999 +0300
@@ -30,16 +30,11 @@
 {
   DBUG_ENTER("hp_clear");
 
-  if (info->block.levels)
-    (void) hp_free_level(&info->block,info->block.levels,info->block.root,
-			(uchar*) 0);
-  info->block.levels=0;
+  hp_clear_dataspace(&info->recordspace);
   hp_clear_keys(info);
-  info->records= info->deleted= 0;
-  info->data_length= 0;
+  info->records= 0;
   info->blength=1;
   info->changed=0;
-  info->del_link=0;
   DBUG_VOID_RETURN;
 }
 
@@ -157,7 +152,7 @@
   int error= 0;
   HP_SHARE *share= info->s;
 
-  if (share->data_length || share->index_length)
+  if (share->recordspace.total_data_length || share->index_length)
     error= HA_ERR_CRASHED;
   else
     if (share->currently_disabled_keys)
diff -ruN a/storage/heap/hp_close.c b/storage/heap/hp_close.c
--- a/storage/heap/hp_close.c	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/hp_close.c	2011-06-02 15:37:43.754916999 +0300
@@ -46,6 +46,10 @@
     heap_open_list=list_delete(heap_open_list,&info->open_list);
   if (!--info->s->open_count && info->s->delete_on_close)
     hp_free(info->s);				/* Table was deleted */
+  if (info->blob_buffer)
+  {
+    my_free(info->blob_buffer);
+  }
   my_free(info);
   DBUG_RETURN(error);
 }
diff -ruN a/storage/heap/hp_create.c b/storage/heap/hp_create.c
--- a/storage/heap/hp_create.c	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/hp_create.c	2011-06-02 15:37:43.754916999 +0300
@@ -14,11 +14,21 @@
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */
 
 #include "heapdef.h"
+#include <mysql_com.h>
+#include <mysqld_error.h>
 
 static int keys_compare(heap_rb_param *param, uchar *key1, uchar *key2);
-static void init_block(HP_BLOCK *block,uint reclength,ulong min_records,
+static void init_block(HP_BLOCK *block,uint chunk_length, ulong min_records,
 		       ulong max_records);
 
+#define FIXED_REC_OVERHEAD (sizeof(uchar))
+#define VARIABLE_REC_OVERHEAD (sizeof(uchar **) + sizeof(uchar))
+
+/* Minimum size that a chunk can take, 12 bytes on 32bit, 24 bytes on 64bit */
+#define VARIABLE_MIN_CHUNK_SIZE                                         \
+  ((sizeof(uchar **) + VARIABLE_REC_OVERHEAD + sizeof(uchar **) - 1) &  \
+   ~(sizeof(uchar **) - 1))
+
 /* Create a heap table */
 
 int heap_create(const char *name, HP_CREATE_INFO *create_info,
@@ -32,6 +42,7 @@
   uint keys= create_info->keys;
   ulong min_records= create_info->min_records;
   ulong max_records= create_info->max_records;
+  ulong max_rows_for_stated_memory;
   DBUG_ENTER("heap_create");
 
   if (!create_info->internal_table)
@@ -48,15 +59,147 @@
 
   if (!share)
   {
+    uint chunk_dataspace_length, chunk_length, is_variable_size;
+    uint fixed_data_length, fixed_column_count;
     HP_KEYDEF *keyinfo;
     DBUG_PRINT("info",("Initializing new table"));
-    
+
+    if (create_info->max_chunk_size)
+    {
+      uint configured_chunk_size= create_info->max_chunk_size;
+
+      /* User requested variable-size records, let's see if they're possible */
+
+      if (configured_chunk_size < create_info->fixed_data_size)
+      {
+        /*
+          The resulting chunk_size cannot be smaller than fixed data part
+          at the start of the first chunk which allows faster copying
+          with a single memcpy().
+        */
+        my_error(ER_CANT_USE_OPTION_HERE, MYF(0), "key_block_size");
+        goto err;
+      }
+
+      if (reclength > configured_chunk_size + VARIABLE_REC_OVERHEAD ||
+	  create_info->blobs > 0)
+      {
+        /*
+          Allow variable size only if we're saving some space, i.e.
+          if a fixed-size record would take more space than variable-size
+          one plus the variable-size overhead.
+          There has to be at least one field after indexed fields.
+          Note that NULL bits are already included in key_part_size.
+        */
+        is_variable_size= 1;
+        chunk_dataspace_length= configured_chunk_size;
+      }
+      else
+      {
+        /* max_chunk_size is near the full reclength, let's use fixed size */
+        is_variable_size= 0;
+        chunk_dataspace_length= reclength;
+      }
+    }
+    else if ((create_info->is_dynamic && reclength >
+              256 + VARIABLE_REC_OVERHEAD)
+             || create_info->blobs > 0)
+    {
+      /*
+        User asked for dynamic records - use 256 as the chunk size, if that
+        will may save some memory. Otherwise revert to fixed size format.
+      */
+      if ((create_info->fixed_data_size + VARIABLE_REC_OVERHEAD) > 256)
+        chunk_dataspace_length= create_info->fixed_data_size;
+      else
+        chunk_dataspace_length= 256 - VARIABLE_REC_OVERHEAD;
+
+      is_variable_size= 1;
+    }
+    else
+    {
+      /*
+        If max_chunk_size is not specified, put the whole record in one chunk
+      */
+      is_variable_size= 0;
+      chunk_dataspace_length= reclength;
+    }
+
+    if (is_variable_size)
+    {
+      /* Check whether we have any variable size records past key data */
+      uint has_variable_fields= 0;
+
+      fixed_data_length= create_info->fixed_data_size;
+      fixed_column_count= create_info->fixed_key_fieldnr;
+
+      for (i= create_info->fixed_key_fieldnr; i < create_info->columns; i++)
+      {
+        HP_COLUMNDEF *column= create_info->columndef + i;
+	if ((column->type == MYSQL_TYPE_VARCHAR &&
+	     (column->length - column->length_bytes) >= 32) ||
+	    column->type == MYSQL_TYPE_BLOB)
+        {
+            /*
+              The field has to be either blob or >= 5.0.3 true VARCHAR
+              and have substantial length.
+              TODO: do we want to calculate minimum length?
+            */
+            has_variable_fields= 1;
+            break;
+        }
+
+        if (has_variable_fields)
+        {
+          break;
+        }
+
+        if ((column->offset + column->length) <= chunk_dataspace_length)
+        {
+          /* Still no variable-size columns, add one fixed-length */
+          fixed_column_count= i + 1;
+          fixed_data_length= column->offset + column->length;
+        }
+      }
+
+      if (!has_variable_fields && create_info->blobs == 0)
+      {
+        /*
+          There is no need to use variable-size records without variable-size
+          columns.
+          Reset sizes if it's not variable size anymore.
+        */
+        is_variable_size= 0;
+        chunk_dataspace_length= reclength;
+        fixed_data_length= reclength;
+        fixed_column_count= create_info->columns;
+      }
+    }
+    else
+    {
+      fixed_data_length= reclength;
+      fixed_column_count= create_info->columns;
+    }
+
     /*
-      We have to store sometimes uchar* del_link in records,
-      so the record length should be at least sizeof(uchar*)
+      We store uchar* del_link inside the data area of deleted records,
+      so the data length should be at least sizeof(uchar*)
     */
-    set_if_bigger(reclength, sizeof (uchar*));
-    
+    set_if_bigger(chunk_dataspace_length, sizeof (uchar **));
+
+    if (is_variable_size)
+    {
+      chunk_length= chunk_dataspace_length + VARIABLE_REC_OVERHEAD;
+    }
+    else
+    {
+      chunk_length= chunk_dataspace_length + FIXED_REC_OVERHEAD;
+    }
+
+    /* Align chunk length to the next pointer */
+    chunk_length= (uint) (chunk_length + sizeof(uchar **) - 1) &
+      ~(sizeof(uchar **) - 1);
+
     for (i= key_segs= max_length= 0, keyinfo= keydef; i < keys; i++, keyinfo++)
     {
       bzero((char*) &keyinfo->block,sizeof(keyinfo->block));
@@ -73,42 +216,11 @@
 	    keyinfo->rb_tree.size_of_element++;
 	}
 	switch (keyinfo->seg[j].type) {
-	case HA_KEYTYPE_SHORT_INT:
-	case HA_KEYTYPE_LONG_INT:
-	case HA_KEYTYPE_FLOAT:
-	case HA_KEYTYPE_DOUBLE:
-	case HA_KEYTYPE_USHORT_INT:
-	case HA_KEYTYPE_ULONG_INT:
-	case HA_KEYTYPE_LONGLONG:
-	case HA_KEYTYPE_ULONGLONG:
-	case HA_KEYTYPE_INT24:
-	case HA_KEYTYPE_UINT24:
-	case HA_KEYTYPE_INT8:
-	  keyinfo->seg[j].flag|= HA_SWAP_KEY;
-          break;
         case HA_KEYTYPE_VARBINARY1:
-          /* Case-insensitiveness is handled in coll->hash_sort */
-          keyinfo->seg[j].type= HA_KEYTYPE_VARTEXT1;
-          /* fall_through */
         case HA_KEYTYPE_VARTEXT1:
-          keyinfo->flag|= HA_VAR_LENGTH_KEY;
-          length+= 2;
-          /* Save number of bytes used to store length */
-          keyinfo->seg[j].bit_start= 1;
-          break;
         case HA_KEYTYPE_VARBINARY2:
-          /* Case-insensitiveness is handled in coll->hash_sort */
-          /* fall_through */
         case HA_KEYTYPE_VARTEXT2:
-          keyinfo->flag|= HA_VAR_LENGTH_KEY;
           length+= 2;
-          /* Save number of bytes used to store length */
-          keyinfo->seg[j].bit_start= 2;
-          /*
-            Make future comparison simpler by only having to check for
-            one type
-          */
-          keyinfo->seg[j].type= HA_KEYTYPE_VARTEXT1;
           break;
 	default:
 	  break;
@@ -133,13 +245,34 @@
     }
     if (!(share= (HP_SHARE*) my_malloc((uint) sizeof(HP_SHARE)+
 				       keys*sizeof(HP_KEYDEF)+
+                                       (create_info->columns *
+                                        sizeof(HP_COLUMNDEF)) +
 				       key_segs*sizeof(HA_KEYSEG),
 				       MYF(MY_ZEROFILL))))
       goto err;
-    share->keydef= (HP_KEYDEF*) (share + 1);
+
+    /*
+      Max_records is used for estimating block sizes and for enforcement.
+      Calculate the very maximum number of rows (if everything was one chunk)
+      and then take either that value or configured max_records (pick smallest
+      one).
+    */
+    max_rows_for_stated_memory= (ha_rows) (create_info->max_table_size /
+                                           (create_info->keys_memory_size +
+                                            chunk_length));
+    max_records = ((max_records && max_records < max_rows_for_stated_memory) ?
+                   max_records : max_rows_for_stated_memory);
+
+    share->column_defs= (HP_COLUMNDEF*) (share + 1);
+    memcpy(share->column_defs, create_info->columndef,
+           (size_t) (sizeof(create_info->columndef[0]) *
+                     create_info->columns));
+
+    share->keydef= (HP_KEYDEF*) (share->column_defs + create_info->columns);
     share->key_stat_version= 1;
     keyseg= (HA_KEYSEG*) (share->keydef + keys);
-    init_block(&share->block, reclength + 1, min_records, max_records);
+    init_block(&share->recordspace.block, chunk_length, min_records,
+               max_records);
 	/* Fix keys */
     memcpy(share->keydef, keydef, (size_t) (sizeof(keydef[0]) * keys));
     for (i= 0, keyinfo= share->keydef; i < keys; i++, keyinfo++)
@@ -177,15 +310,35 @@
     share->min_records= min_records;
     share->max_records= max_records;
     share->max_table_size= create_info->max_table_size;
-    share->data_length= share->index_length= 0;
-    share->reclength= reclength;
+    share->index_length= 0;
     share->blength= 1;
     share->keys= keys;
     share->max_key_length= max_length;
+    share->column_count= create_info->columns;
     share->changed= 0;
     share->auto_key= create_info->auto_key;
     share->auto_key_type= create_info->auto_key_type;
     share->auto_increment= create_info->auto_increment;
+
+    share->fixed_data_length= fixed_data_length;
+    share->fixed_column_count= fixed_column_count;
+    share->blobs= create_info->blobs;
+
+    share->recordspace.chunk_length= chunk_length;
+    share->recordspace.chunk_dataspace_length= chunk_dataspace_length;
+    share->recordspace.is_variable_size= is_variable_size;
+    share->recordspace.total_data_length= 0;
+
+    if (is_variable_size) {
+      share->recordspace.offset_link= chunk_dataspace_length;
+      share->recordspace.offset_status= share->recordspace.offset_link +
+        sizeof(uchar **);
+    } else {
+      /* Make it likely to fail if anyone uses this offset */
+      share->recordspace.offset_link= 1 << 22;
+      share->recordspace.offset_status= chunk_dataspace_length;
+    }
+
     /* Must be allocated separately for rename to work */
     if (!(share->name= my_strdup(name,MYF(0))))
     {
@@ -227,7 +380,7 @@
 		    param->search_flag, not_used);
 }
 
-static void init_block(HP_BLOCK *block, uint reclength, ulong min_records,
+static void init_block(HP_BLOCK *block, uint chunk_length, ulong min_records,
 		       ulong max_records)
 {
   uint i,recbuffer,records_in_block;
@@ -235,7 +388,12 @@
   max_records= max(min_records,max_records);
   if (!max_records)
     max_records= 1000;			/* As good as quess as anything */
-  recbuffer= (uint) (reclength + sizeof(uchar**) - 1) & ~(sizeof(uchar**) - 1);
+  /*
+    We want to start each chunk at 8 bytes boundary, round recbuffer to the
+    next 8.
+  */
+  recbuffer= (uint) (chunk_length + sizeof(uchar**) - 1) &
+    ~(sizeof(uchar**) - 1);
   records_in_block= max_records / 10;
   if (records_in_block < 10 && max_records)
     records_in_block= 10;
diff -ruN a/storage/heap/hp_delete.c b/storage/heap/hp_delete.c
--- a/storage/heap/hp_delete.c	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/hp_delete.c	2011-06-02 15:37:43.754916999 +0300
@@ -22,6 +22,8 @@
   uchar *pos;
   HP_SHARE *share=info->s;
   HP_KEYDEF *keydef, *end, *p_lastinx;
+  uint rec_length, chunk_count;
+
   DBUG_ENTER("heap_delete");
   DBUG_PRINT("enter",("info: 0x%lx  record: 0x%lx", (long) info, (long) record));
 
@@ -31,6 +33,8 @@
     DBUG_RETURN(my_errno);			/* Record changed */
   share->changed=1;
 
+  rec_length = hp_get_encoded_data_length(share, record, &chunk_count);
+
   if ( --(share->records) < share->blength >> 1) share->blength>>=1;
   pos=info->current_ptr;
 
@@ -43,10 +47,7 @@
   }
 
   info->update=HA_STATE_DELETED;
-  *((uchar**) pos)=share->del_link;
-  share->del_link=pos;
-  pos[share->reclength]=0;		/* Record deleted */
-  share->deleted++;
+  hp_free_chunks(&share->recordspace, pos);
   info->current_hash_ptr=0;
 #if !defined(DBUG_OFF) && defined(EXTRA_HEAP_DEBUG)
   DBUG_EXECUTE("check_heap",heap_check_heap(info, 0););
@@ -75,7 +76,8 @@
     info->last_pos= NULL; /* For heap_rnext/heap_rprev */
 
   custom_arg.keyseg= keyinfo->seg;
-  custom_arg.key_length= hp_rb_make_key(keyinfo, info->recbuf, record, recpos);
+  custom_arg.key_length= hp_rb_make_key(keyinfo, info->recbuf, record, recpos,
+                                        FALSE);
   custom_arg.search_flag= SEARCH_SAME;
   old_allocated= keyinfo->rb_tree.allocated;
   res= tree_delete(&keyinfo->rb_tree, info->recbuf, custom_arg.key_length,
@@ -112,6 +114,7 @@
   blength=share->blength;
   if (share->records+1 == blength)
     blength+= blength;
+
   lastpos=hp_find_hash(&keyinfo->block,share->records);
   last_ptr=0;
 
diff -ruN /dev/null b/storage/heap/hp_dspace.c
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ b/storage/heap/hp_dspace.c	2011-06-02 15:40:14.104917001 +0300
@@ -0,0 +1,440 @@
+/* Copyright (C) 2000-2002 MySQL AB
+   Copyright (C) 2008 eBay, Inc
+
+   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; version 2 of the License.
+
+   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 */
+
+/*
+  Implements various base dataspace-related functions - allocate, free, clear
+*/
+
+#include "heapdef.h"
+
+
+/*
+  MySQL Heap tables keep data in arrays of fixed-size chunks.
+  These chunks are organized into two groups of HP_BLOCK structures:
+    - group1 contains indexes, with one HP_BLOCK per key
+      (part of HP_KEYDEF)
+    - group2 contains record data, with single HP_BLOCK
+      for all records, referenced by HP_SHARE.recordspace.block
+
+  While columns used in index are usually small, other columns
+  in the table may need to accomodate larger data. Typically,
+  larger data is placed into VARCHAR or BLOB columns. With actual
+  sizes varying, Heap Engine has to support variable-sized records
+  in memory. Heap Engine implements the concept of dataspace
+  (HP_DATASPACE), which incorporates HP_BLOCK for the record data,
+  and adds more information for managing variable-sized records.
+
+  Variable-size records are stored in multiple "chunks",
+  which means that a single record of data (database "row") can
+  consist of multiple chunks organized into one "set". HP_BLOCK
+  contains chunks. In variable-size format, one record
+  is represented as one or many chunks, depending on the actual
+  data, while in fixed-size mode, one record is always represented
+  as one chunk. The index structures would always point to the first
+  chunk in the chunkset.
+
+  At the time of table creation, Heap Engine attempts to find out if
+  variable-size records are desired. A user can request
+  variable-size records by providing either row_type=dynamic or
+  key_block_size=NNN table create option. Heap Engine will check
+  whether key_block_size provides enough space in the first chunk
+  to keep all null bits and columns that are used in indexes.
+  If key_block_size is too small, table creation will be aborted
+  with an error. Heap Engine will revert to fixed-size allocation
+  mode if key_block_size provides no memory benefits (if the
+  fixed-size record would always be shorter then the first chunk
+  in the chunkset with the specified key_block_size).
+
+  In order to improve index search performance, Heap Engine needs
+  to keep all null flags and all columns used as keys inside
+  the first chunk of a chunkset. In particular, this means that
+  all columns used as keys should be defined first in the table
+  creation SQL. The length of data used by null bits and key columns
+  is stored as fixed_data_length inside HP_SHARE. fixed_data_length
+  will extend past last key column if more fixed-length fields can
+  fit into the first chunk.
+
+  Variable-size records are necessary only in the presence of
+  variable-size columns. Heap Engine will be looking for BLOB
+  columns or VARCHAR columns, which declare length of 32 or more. If
+  no such columns are found, table will be switched to fixed-size
+  format. You should always try to put such columns at the end of
+  the table definition.
+
+  Whenever data is being inserted or updated in the table
+  Heap Engine will calculate how many chunks are necessary.
+  For insert operations, Heap Engine allocates new chunkset in
+  the recordspace. For update operations it will modify length of
+  the existing chunkset, unlinking unnecessary chunks at the end,
+  or allocating and adding more if larger length is necessary.
+
+  When writing data to chunks or copying data back to record,
+  fixed-size columns are copied in their full format. VARCHARs and
+  BLOBs are copied based on their actual length. Any NULL values
+  after fixed_data_length are skipped.
+
+  The allocation and contents of the actual chunks varies between
+  fixed and variable-size modes. Total chunk length is always
+  aligned to the next sizeof(uchar*). Here is the format of
+  fixed-size chunk:
+      uchar[] - sizeof=chunk_dataspace_length, but at least
+                sizeof(uchar*) bytes. Keeps actual data or pointer
+                to the next deleted chunk.
+                chunk_dataspace_length equals to full record length
+      uchar   - status field (1 means "in use", 0 means "deleted")
+
+  Variable-size chunk uses different format:
+      uchar[] - sizeof=chunk_dataspace_length, but at least
+                sizeof(uchar*) bytes. Keeps actual data or pointer
+                to the next deleted chunk.
+                chunk_dataspace_length is set according to table
+                setup (key_block_size)
+      uchar*  - pointer to the next chunk in this chunkset,
+                or NULL for the last chunk
+      uchar   - status field (1 means "first", 0 means "deleted",
+                2 means "linked")
+
+  When allocating a new chunkset of N chunks, Heap Engine will try
+  to allocate chunks one-by-one, linking them as they become
+  allocated. Allocation of a single chunk will attempt to reuse
+  a deleted (freed) chunk. If no free chunks are available,
+  it will attempt to allocate a new area inside HP_BLOCK.
+  Freeing chunks will place them at the front of free list
+  referenced by del_link in HP_DATASPACE. The newly freed chunk
+  will contain reference to the previously freed chunk in its first
+  sizeof(uchar*) of the payload space.
+
+  Here is open issues:
+    -  It is not very nice to require people to keep key columns
+       at the beginning of the table creation SQL. There are three
+       proposed resolutions:
+       a. Leave it as is. It's a reasonable limitation
+       b. Add new HA_KEEP_KEY_COLUMNS_TO_FRONT flag to handler.h and
+          make table.cpp align columns when it creates the table
+       c. Make HeapEngine reorder columns in the chunk data, so that
+          key columns go first. Add parallel HA_KEYSEG structures
+          to distinguish positions in record vs. positions in
+          the first chunk. Copy all data field-by-field rather than
+          using single memcpy unless DBA kept key columns to
+          the beginning.
+    -  heap_check_heap needs verify linked chunks, looking for
+       issues such as orphans, cycles, and bad links. However,
+       Heap Engine today does not do similar things even for
+       free list.
+    -  In a more sophisticated implementation, some space can
+       be saved even with all fixed-size columns if many of them
+       have NULL value, as long as these columns are not used
+       in indexes
+    -  In variable-size format status should be moved to lower
+       bits of the "next" pointer. Pointer is always aligned
+       to sizeof(byte*), which is at least 4, leaving 2 lower
+       bits free. This will save 8 bytes per chunk
+       on 64-bit platform.
+    -  As we do not want to modify FRM format or to add new SQL
+       keywords, KEY_BLOCK_SIZE option of "CREATE TABLE" is reused
+       to specify block size for Heap Engine tables.
+    -  since all key columns must fit in the first chunk, having keys
+       on BLOB columns is currently impossible. This limitation is
+       relatively easiy to remove in future.
+*/
+
+static uchar *hp_allocate_one_chunk(HP_DATASPACE *info);
+
+
+/**
+  Clear a dataspace
+
+  Frees memory and zeros-out any relevant counters in the dataspace
+
+  @param  info  the dataspace to clear
+*/
+
+void hp_clear_dataspace(HP_DATASPACE *info)
+{
+  if (info->block.levels)
+  {
+    hp_free_level(&info->block,info->block.levels,info->block.root,
+                  (uchar *) 0);
+  }
+  info->block.levels= 0;
+  info->del_chunk_count= info->chunk_count= 0;
+  info->del_link= 0;
+  info->total_data_length= 0;
+}
+
+
+/**
+  Allocate or reallocate a chunkset in the dataspace
+
+  Attempts to allocate a new chunkset or change the size of an existing chunkset
+
+  @param  info            the hosting dataspace
+  @param  chunk_count     the number of chunks that we expect as the result
+  @param  existing_set    non-null value asks function to resize existing
+                          chunkset, return value would point to this set
+
+  @return  Pointer to the first chunk in the new or updated chunkset, or NULL
+           if unsuccessful
+*/
+
+static uchar *hp_allocate_variable_chunkset(HP_DATASPACE *info,
+                                           uint chunk_count,
+                                           uchar *existing_set)
+{
+  int alloc_count= chunk_count, i;
+  uchar *first_chunk= 0, *curr_chunk= 0, *prev_chunk= 0;
+  uchar  *last_existing_chunk= 0;
+
+  DBUG_ASSERT(alloc_count);
+
+  if (existing_set)
+  {
+    first_chunk= existing_set;
+
+    curr_chunk= existing_set;
+    while (curr_chunk && alloc_count)
+    {
+      prev_chunk= curr_chunk;
+      curr_chunk= *((uchar **) (curr_chunk + info->offset_link));
+      alloc_count--;
+    }
+
+    if (!alloc_count)
+    {
+      if (curr_chunk)
+      {
+        /*
+          We came through all chunks and there is more left, let's truncate the
+          list.
+        */
+        *((uchar **) (prev_chunk + info->offset_link))= NULL;
+        hp_free_chunks(info, curr_chunk);
+      }
+
+      return first_chunk;
+    }
+
+    last_existing_chunk= prev_chunk;
+  }
+
+  /*
+    We can reach this point only if we're allocating new chunkset or more chunks
+    in existing set.
+  */
+
+  for (i= 0; i < alloc_count; i++)
+  {
+    curr_chunk= hp_allocate_one_chunk(info);
+    if (!curr_chunk)
+    {
+      /* no space in the current block */
+
+      if (last_existing_chunk)
+      {
+        /* Truncate whatever was added at the end of the existing chunkset */
+        prev_chunk= last_existing_chunk;
+        curr_chunk= *((uchar **)(prev_chunk + info->offset_link));
+        *((uchar **)(prev_chunk + info->offset_link))= NULL;
+        hp_free_chunks(info, curr_chunk);
+      }
+      else if (first_chunk)
+      {
+        /* free any chunks previously allocated */
+        hp_free_chunks(info, first_chunk);
+      }
+
+      return NULL;
+    }
+
+    /* mark as if this chunk is last in the chunkset */
+    *((uchar **) (curr_chunk + info->offset_link))= 0;
+
+    if (prev_chunk)
+    {
+      /* tie them into a linked list */
+      *((uchar **) (prev_chunk + info->offset_link))= curr_chunk;
+      /* Record linked from active */
+      curr_chunk[info->offset_status]= CHUNK_STATUS_LINKED;
+    }
+    else
+    {
+      /* Record active */
+      curr_chunk[info->offset_status]= CHUNK_STATUS_ACTIVE;
+    }
+
+    if (!first_chunk)
+    {
+      first_chunk= curr_chunk;
+    }
+
+    prev_chunk= curr_chunk;
+}
+
+  return first_chunk;
+}
+
+
+/**
+  Allocate a new chunkset in the dataspace
+
+  Attempts to allocate a new chunkset
+
+  @param  info            the hosting dataspace
+  @param  chunk_count     the number of chunks that we expect as the result
+
+  @return  Pointer to the first chunk in the new or updated chunkset, or NULL if
+           unsuccessful
+*/
+
+uchar *hp_allocate_chunkset(HP_DATASPACE *info, uint chunk_count)
+{
+  uchar *result;
+
+  DBUG_ENTER("hp_allocate_chunks");
+
+  if (info->is_variable_size)
+  {
+    result = hp_allocate_variable_chunkset(info, chunk_count, NULL);
+  }
+  else
+  {
+    result= hp_allocate_one_chunk(info);
+    if (result)
+    {
+      result[info->offset_status]= CHUNK_STATUS_ACTIVE;
+    }
+
+    DBUG_RETURN(result);
+  }
+
+  DBUG_RETURN(result);
+}
+
+
+/**
+  Reallocate an existing chunkset in the dataspace
+
+  Attempts to change the size of an existing chunkset
+
+  @param  info            the hosting dataspace
+  @param  chunk_count     the number of chunks that we expect as the result
+  @param  pos             pointer to the existing chunkset
+
+  @return  Error code or zero if successful
+*/
+
+int hp_reallocate_chunkset(HP_DATASPACE *info, uint chunk_count, uchar *pos)
+{
+  DBUG_ENTER("hp_reallocate_chunks");
+
+  if (!info->is_variable_size)
+  {
+    /* Update should never change chunk_count in fixed-size mode */
+    my_errno= HA_ERR_WRONG_COMMAND;
+    return my_errno;
+  }
+
+  /* Reallocate never moves the first chunk */
+  if (!hp_allocate_variable_chunkset(info, chunk_count, pos))
+    DBUG_RETURN(my_errno);
+
+  DBUG_RETURN(0);
+}
+
+
+/**
+  Allocate a single chunk in the dataspace
+
+  Attempts to allocate a new chunk or reuse one from deleted list
+
+  @param  info            the hosting dataspace
+
+  @return  Pointer to the chunk, or NULL if unsuccessful
+*/
+
+static uchar *hp_allocate_one_chunk(HP_DATASPACE *info)
+{
+  uchar *curr_chunk;
+  size_t length;
+  ulong block_pos;
+
+  if (info->del_link)
+  {
+    curr_chunk= info->del_link;
+    info->del_link= *((uchar **) curr_chunk);
+    info->del_chunk_count--;
+
+    DBUG_PRINT("hp_allocate_one_chunk",
+               ("Used old position: 0x%lx",(long) curr_chunk));
+    return curr_chunk;
+  }
+
+  block_pos= (info->chunk_count % info->block.records_in_block);
+  if (!block_pos)
+  {
+    if (hp_get_new_block(&info->block, &length))
+    {
+      /* no space in the current block */
+      return NULL;
+    }
+
+    info->total_data_length+= length;
+  }
+
+  info->chunk_count++;
+  curr_chunk= ((uchar *) info->block.level_info[0].last_blocks +
+               block_pos * info->block.recbuffer);
+
+  DBUG_PRINT("hp_allocate_one_chunk",
+             ("Used new position: 0x%lx", (long) curr_chunk));
+
+  return curr_chunk;
+}
+
+
+/**
+  Free a list of chunks
+
+  Reclaims all chunks linked by the pointer,
+  which could be the whole chunkset or a part of an existing chunkset
+
+  @param  info            the hosting dataspace
+  @param  pos             pointer to the head of the chunkset
+*/
+
+void hp_free_chunks(HP_DATASPACE *info, uchar *pos)
+{
+  uchar *curr_chunk= pos;
+
+  while (curr_chunk)
+  {
+    info->del_chunk_count++;
+    *((uchar **) curr_chunk)= info->del_link;
+    info->del_link= curr_chunk;
+
+    curr_chunk[info->offset_status]= CHUNK_STATUS_DELETED;
+
+    DBUG_PRINT("hp_free_chunks",("Freed position: 0x%lx", (long) curr_chunk));
+
+    if (!info->is_variable_size)
+    {
+      break;
+    }
+
+    /* Delete next chunk in this chunkset */
+    curr_chunk= *((uchar **)(curr_chunk + info->offset_link));
+  }
+}
diff -ruN a/storage/heap/hp_extra.c b/storage/heap/hp_extra.c
--- a/storage/heap/hp_extra.c	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/hp_extra.c	2011-06-02 15:37:57.814917006 +0300
@@ -56,7 +56,6 @@
   info->current_record= (ulong) ~0L;
   info->current_hash_ptr=0;
   info->update=0;
-  info->next_block=0;
   return 0;
 }
 
diff -ruN a/storage/heap/hp_hash.c b/storage/heap/hp_hash.c
--- a/storage/heap/hp_hash.c	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/hp_hash.c	2011-06-02 15:37:57.824916999 +0300
@@ -336,16 +336,26 @@
     {
       CHARSET_INFO *cs= seg->charset;
       uint pack_length= seg->bit_start;
-      uint length= (pack_length == 1 ? (uint) *(uchar*) pos : uint2korr(pos));
+      uint length= hp_calc_blob_length(pack_length, pos);
+
+      if (seg->flag & HA_BLOB_PART)
+      {
+        memcpy(&pos, pos + pack_length, sizeof(char *));
+      }
+      else
+      {
+        pos+= pack_length;
+      }
+
       if (cs->mbmaxlen > 1)
       {
         uint char_length;
-        char_length= my_charpos(cs, pos + pack_length,
-                                pos + pack_length + length,
+        char_length= my_charpos(cs, pos,
+                                pos + length,
                                 seg->length/cs->mbmaxlen);
         set_if_smaller(length, char_length);
       }
-      cs->coll->hash_sort(cs, pos+pack_length, length, &nr, &nr2);
+      cs->coll->hash_sort(cs, pos, length, &nr, &nr2);
     }
     else
     {
@@ -545,18 +555,18 @@
       uint char_length1, char_length2;
       uint pack_length= seg->bit_start;
       CHARSET_INFO *cs= seg->charset;
-      if (pack_length == 1)
-      {
-        char_length1= (uint) *(uchar*) pos1++;
-        char_length2= (uint) *(uchar*) pos2++;
-      }
-      else
+
+      char_length1= hp_calc_blob_length(pack_length, pos1);
+      char_length2= hp_calc_blob_length(pack_length, pos2);
+      pos1+= pack_length;
+      pos2+= pack_length;
+
+      if (seg->flag & HA_BLOB_PART)
       {
-        char_length1= uint2korr(pos1);
-        char_length2= uint2korr(pos2);
-        pos1+= 2;
-        pos2+= 2;
+        memcpy(&pos1, pos1, sizeof(char *));
+        memcpy(&pos2, pos2, sizeof(char *));
       }
+
       if (cs->mbmaxlen > 1)
       {
         uint safe_length1= char_length1;
@@ -668,6 +678,34 @@
 }
 
 
+/**
+   Returns a BLOB length stored in the specified number of bytes at the
+   specified location.
+
+   @param length       the number of bytes used to store length
+   @param pos          pointer to length bytes
+
+   @return  Length of BLOB data.
+*/
+
+uint hp_calc_blob_length(uint bytes, const uchar *pos)
+{
+  switch (bytes) {
+  case 1:
+    return (uint) *pos;
+  case 2:
+    return uint2korr(pos);
+  case 3:
+    return uint3korr(pos);
+  case 4:
+    return uint4korr(pos);
+  default:
+    break;
+  }
+
+  return 0; /* Impossible */
+}
+
 	/* Copy a key from a record to a keybuffer */
 
 void hp_make_key(HP_KEYDEF *keydef, uchar *key, const uchar *rec)
@@ -678,18 +716,37 @@
   {
     CHARSET_INFO *cs= seg->charset;
     uint char_length= seg->length;
-    uchar *pos= (uchar*) rec + seg->start;
+    const uchar *pos= rec + seg->start;
     if (seg->null_bit)
       *key++= test(rec[seg->null_pos] & seg->null_bit);
-    if (cs->mbmaxlen > 1)
+
+    if (seg->flag & HA_BLOB_PART)
     {
-      char_length= my_charpos(cs, pos, pos + seg->length,
-                              char_length / cs->mbmaxlen);
-      set_if_smaller(char_length, seg->length); /* QQ: ok to remove? */
-    }
-    if (seg->type == HA_KEYTYPE_VARTEXT1)
-      char_length+= seg->bit_start;             /* Copy also length */
-    memcpy(key,rec+seg->start,(size_t) char_length);
+      uint tmp_length= hp_calc_blob_length(seg->bit_start, pos);
+      uint length= min(seg->length, tmp_length);
+
+      memcpy(&pos, rec + seg->bit_start, sizeof(char *));
+      if (cs->mbmaxlen > 1)
+      {
+        char_length= my_charpos(cs, pos, pos + seg->length,
+                                char_length / cs->mbmaxlen);
+        set_if_smaller(char_length, length); /* QQ: ok to remove? */
+      }
+      store_key_length_inc(key, char_length);
+    }
+    else
+    {
+      if (cs->mbmaxlen > 1)
+      {
+        char_length= my_charpos(cs, pos, pos + seg->length,
+                                char_length / cs->mbmaxlen);
+        set_if_smaller(char_length, seg->length); /* QQ: ok to remove? */
+      }
+      if (seg->type == HA_KEYTYPE_VARTEXT1)
+        char_length+= seg->bit_start;             /* Copy also length */
+    }
+
+    memcpy(key, pos, (size_t) char_length);
     key+= char_length;
   }
 }
@@ -702,8 +759,8 @@
   } while(0)
 
 
-uint hp_rb_make_key(HP_KEYDEF *keydef, uchar *key, 
-		    const uchar *rec, uchar *recpos)
+uint hp_rb_make_key(HP_KEYDEF *keydef, uchar *key,
+                    const uchar *rec, uchar *recpos, my_bool packed)
 {
   uchar *start_key= key;
   HA_KEYSEG *seg, *endseg;
@@ -772,6 +829,29 @@
       key+= char_length;
       continue;
     }
+    else if (seg->flag & HA_BLOB_PART)
+    {
+      uchar *pos=      (uchar*) rec + seg->start;
+      uint tmp_length= hp_calc_blob_length(seg->bit_start, pos);
+      uint length= min(seg->length, tmp_length);
+      CHARSET_INFO *cs= seg->charset;
+      char_length= seg->length / cs->mbmaxlen;
+
+      /* check_one_rb_key() calls hp_rb_make_key() for already packed records */
+      if (!packed)
+      {
+        memcpy(&pos, pos + seg->bit_start, sizeof(char *));
+      }
+      else
+      {
+        pos+= seg->bit_start;
+      }
+      FIX_LENGTH(cs, pos, length, char_length);
+      store_key_length_inc(key, char_length);
+      memcpy(key, pos, (size_t) char_length);
+      key+= char_length;
+      continue;
+    }
 
     char_length= seg->length;
     if (seg->charset->mbmaxlen > 1)
diff -ruN a/storage/heap/hp_info.c b/storage/heap/hp_info.c
--- a/storage/heap/hp_info.c	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/hp_info.c	2011-06-02 15:37:57.824916999 +0300
@@ -47,9 +47,22 @@
 {
   DBUG_ENTER("heap_info");
   x->records         = info->s->records;
-  x->deleted         = info->s->deleted;
-  x->reclength       = info->s->reclength;
-  x->data_length     = info->s->data_length;
+  x->deleted         = info->s->recordspace.del_chunk_count;
+
+  if (info->s->recordspace.is_variable_size)
+  {
+    if (info->s->records)
+      x->reclength   = (uint) (info->s->recordspace.total_data_length /
+                               (ulonglong) info->s->records);
+    else
+      x->reclength   = info->s->recordspace.chunk_length;
+  }
+  else
+  {
+    x->reclength     = info->s->recordspace.chunk_dataspace_length;
+  }
+
+  x->data_length     = info->s->recordspace.total_data_length;
   x->index_length    = info->s->index_length;
   x->max_records     = info->s->max_records;
   x->errkey          = info->errkey;
diff -ruN a/storage/heap/hp_open.c b/storage/heap/hp_open.c
--- a/storage/heap/hp_open.c	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/hp_open.c	2011-06-02 15:37:57.824916999 +0300
@@ -47,9 +47,9 @@
 #ifndef DBUG_OFF
   info->opt_flag= READ_CHECK_USED;		/* Check when changing */
 #endif
-  DBUG_PRINT("exit",("heap: 0x%lx  reclength: %d  records_in_block: %d",
-		     (long) info, share->reclength,
-                     share->block.records_in_block));
+  DBUG_PRINT("exit",("heap: 0x%lx  chunk_length: %d  records_in_block: %d",
+                     (long) info, share->recordspace.chunk_length,
+                     share->recordspace.block.records_in_block));
   DBUG_RETURN(info);
 }
 
diff -ruN /dev/null b/storage/heap/hp_record.c
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ b/storage/heap/hp_record.c	2011-06-02 15:40:21.634916999 +0300
@@ -0,0 +1,498 @@
+/* Copyright (C) 2000-2002 MySQL AB
+   Copyright (C) 2008 eBay, Inc
+
+   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; version 2 of the License.
+
+   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 */
+
+/*
+  Implements various base record-related functions, such as encode and decode
+  into chunks.
+*/
+
+#include "heapdef.h"
+#include <mysql_com.h>
+
+/**
+  Calculate size of the record for the purpose of storing in chunks
+
+  Walk through the fields of the record and calculates the exact space
+  needed in chunks as well the the total chunk count
+
+  @param       info         the hosting table
+  @param       record       the record in standard unpacked format
+  @param[out]  chunk_count  the number of chunks needed for this record
+
+  @return The size of the required storage in bytes
+*/
+
+uint hp_get_encoded_data_length(HP_SHARE *info, const uchar *record,
+                                uint *chunk_count)
+{
+  uint i, dst_offset;
+
+  dst_offset= info->fixed_data_length;
+
+  if (!info->recordspace.is_variable_size)
+  {
+    /* Nothing more to copy */
+    *chunk_count= 1;
+    return dst_offset;
+  }
+
+  for (i= info->fixed_column_count; i < info->column_count; i++)
+  {
+    uint src_offset, length;
+
+    HP_COLUMNDEF *column= info->column_defs + i;
+
+    if (column->null_bit)
+    {
+      if (record[column->null_pos] & column->null_bit)
+      {
+        /* Skip all NULL values */
+        continue;
+      }
+    }
+
+    src_offset= column->offset;
+    if (column->type == MYSQL_TYPE_VARCHAR)
+    {
+      uint pack_length;
+
+      /* >= 5.0.3 true VARCHAR */
+
+      pack_length= column->length_bytes;
+      length= pack_length + (pack_length == 1 ?
+                             (uint) *(uchar *) (record + src_offset) :
+                             uint2korr(record + src_offset));
+    }
+    else if (column->type == MYSQL_TYPE_BLOB)
+    {
+      uint pack_length= column->length_bytes;
+
+      length= pack_length + hp_calc_blob_length(pack_length,
+                                                record + src_offset);
+    }
+    else
+    {
+      length= column->length;
+    }
+
+    dst_offset+= length;
+  }
+
+  *chunk_count= get_chunk_count(&info->recordspace, dst_offset);
+
+  return dst_offset;
+}
+
+
+#if !defined(DBUG_OFF) && defined(EXTRA_HEAP_DEBUG)
+static void dump_chunk(HP_SHARE *info, const uchar *curr_chunk)
+{
+  uint i;
+  fprintf(stdout, "Chunk dump at 0x%lx: ", (long) curr_chunk);
+  for (i= 0; i < info->recordspace.chunk_dataspace_length; i++)
+  {
+    uint b= *((uchar *)(curr_chunk + i));
+    if (b < 0x10)
+    {
+      fprintf(stdout, "0");
+    }
+    fprintf(stdout, "%lx ", (long) b);
+  }
+  fprintf(stdout, ". Next = 0x%lx, Status = %d\n",
+          (long) (*((uchar **) (curr_chunk + info->recordspace.offset_link))),
+          (uint) (*((uchar *) (curr_chunk + info->recordspace.offset_status))));
+}
+#endif
+
+/**
+  Stores data from packed field into the preallocated chunkset,
+  or performs data comparison
+
+  @param  info         the hosting table
+  @param  data         the field data in packed format
+  @param  length       the field data length
+  @param  pos_ptr      the target chunkset
+  @param  off_ptr      the pointer to the offset within the current chunkset
+  @param  is_compare   flag indicating whether we should compare data or store
+                       it
+
+  @return  Status of comparison
+    @retval  non-zero  if comparison found data differences
+    @retval  zero      otherwise
+*/
+
+static inline uint
+hp_process_field_data_to_chunkset(HP_SHARE *info, const uchar *data,
+                                  uint length, uchar **pos_ptr, uint *off_ptr,
+                                  uint is_compare)
+{
+  uint to_copy;
+  uchar *curr_chunk= *pos_ptr;
+  uint dst_offset= *off_ptr;
+  uint rc= 1;
+
+  while (length > 0)
+  {
+
+    to_copy= info->recordspace.chunk_dataspace_length - dst_offset;
+    if (to_copy == 0)
+    {
+      /* Jump to the next chunk */
+#if !defined(DBUG_OFF) && defined(EXTRA_HEAP_DEBUG)
+      dump_chunk(info, curr_chunk);
+#endif
+      curr_chunk= *((uchar **) (curr_chunk + info->recordspace.offset_link));
+      dst_offset= 0;
+      continue;
+    }
+
+    to_copy= min(length, to_copy);
+
+    if (is_compare)
+    {
+      if (memcmp(curr_chunk + dst_offset, data, (size_t) to_copy))
+      {
+        goto end;
+      }
+    }
+    else
+    {
+      memcpy(curr_chunk + dst_offset, data, (size_t) to_copy);
+    }
+
+    data+= to_copy;
+    dst_offset+= to_copy;
+    length-= to_copy;
+  }
+
+  rc= 0;
+
+end:
+  *pos_ptr= curr_chunk;
+  *off_ptr= dst_offset;
+
+  return rc;
+}
+
+/**
+  Encodes or compares record
+
+  Copies data from original unpacked record into the preallocated chunkset,
+  or performs data comparison
+
+  @param  info         the hosting table
+  @param  record       the record in standard unpacked format
+  @param  pos          the target chunkset
+  @param  is_compare   flag indicating whether we should compare data or store
+                       it
+
+  @return  Status of comparison
+    @retval  non-zero  if comparison fond data differences
+    @retval  zero      otherwise
+*/
+
+uint hp_process_record_data_to_chunkset(HP_SHARE *info, const uchar *record,
+                                        uchar *pos, uint is_compare)
+{
+  uint i, dst_offset;
+  uchar *curr_chunk= pos;
+
+  if (is_compare)
+  {
+    if (memcmp(curr_chunk, record, (size_t) info->fixed_data_length))
+    {
+      return 1;
+    }
+  }
+  else
+  {
+    memcpy(curr_chunk, record, (size_t) info->fixed_data_length);
+  }
+
+  if (!info->recordspace.is_variable_size)
+  {
+    /* Nothing more to copy */
+    return 0;
+  }
+
+  dst_offset= info->fixed_data_length;
+
+  for (i= info->fixed_column_count; i < info->column_count; i++)
+  {
+    uint length;
+    const uchar *data;
+
+    HP_COLUMNDEF *column= info->column_defs + i;
+
+    if (column->null_bit)
+    {
+      if (record[column->null_pos] & column->null_bit)
+      {
+        /* Skip all NULL values */
+        continue;
+      }
+    }
+
+    data= record + column->offset;
+    if (column->type == MYSQL_TYPE_VARCHAR)
+    {
+      uint pack_length;
+
+      /* >= 5.0.3 true VARCHAR */
+
+      /* Make sure to copy length indicator and actuals string bytes */
+      pack_length= column->length_bytes;
+      length= pack_length + (pack_length == 1 ? (uint) *data : uint2korr(data));
+    }
+    else if (column->type == MYSQL_TYPE_BLOB)
+    {
+      uint pack_length;
+
+      pack_length= column->length_bytes;
+      /* Just want to store the length, so not interested in the return code */
+      (void) hp_process_field_data_to_chunkset(info, data, pack_length,
+                                               &curr_chunk, &dst_offset, 0);
+      length= hp_calc_blob_length(pack_length, data);
+      memcpy(&data, data + pack_length, sizeof(char *));
+    }
+    else
+    {
+      length= column->length;
+    }
+
+    if (hp_process_field_data_to_chunkset(info, data, length, &curr_chunk,
+                                          &dst_offset, is_compare))
+    {
+      return 1;
+    }
+  }
+
+#if !defined(DBUG_OFF) && defined(EXTRA_HEAP_DEBUG)
+  dump_chunk(info, curr_chunk);
+#endif
+
+  return 0;
+}
+
+
+/**
+  Stores record in the heap table chunks
+
+  Copies data from original unpacked record into the preallocated chunkset
+
+  @param  info         the hosting table
+  @param  record       the record in standard unpacked format
+  @param  pos          the target chunkset
+*/
+
+void hp_copy_record_data_to_chunkset(HP_SHARE *info, const uchar *record,
+                                     uchar *pos)
+{
+  DBUG_ENTER("hp_copy_record_data_to_chunks");
+
+  hp_process_record_data_to_chunkset(info, record, pos, 0);
+
+  DBUG_VOID_RETURN;
+}
+
+
+/*
+  Macro to switch curr_chunk to the next chunk in the chunkset and reset
+  src_offset.
+*/
+#if !defined(DBUG_OFF) && defined(EXTRA_HEAP_DEBUG)
+#define SWITCH_TO_NEXT_CHUNK_FOR_READ(share, curr_chunk, src_offset)     \
+  {                                                                     \
+    curr_chunk= *((uchar**) (curr_chunk + share->recordspace.offset_link)); \
+    src_offset= 0;                                                      \
+    dump_chunk(share, curr_chunk);                                       \
+  }
+#else
+#define SWITCH_TO_NEXT_CHUNK_FOR_READ(share, curr_chunk, src_offset)     \
+  {                                                                     \
+    curr_chunk= *((uchar**) (curr_chunk + share->recordspace.offset_link)); \
+    src_offset= 0;                                                      \
+  }
+#endif
+
+/**
+  Copies record data from storage to unpacked record format
+
+  Copies data from chunkset into its original unpacked record
+
+  @param       info         the hosting table
+  @param[out]  record       the target record in standard unpacked format
+  @param       pos          the source chunkset
+
+  @return                   Status of conversion
+    @retval   0             success
+    @retval   1             out of memory
+*/
+
+int hp_extract_record(HP_INFO *info, uchar *record, const uchar *pos)
+{
+  uint i, src_offset;
+  const uchar *curr_chunk= pos;
+  HP_SHARE *share= info->s;
+  uint *rec_offsets;
+  uint *buf_offsets;
+  uint nblobs= 0;
+  uint init_offset= share->blobs * sizeof(uint) * 2;
+
+  DBUG_ENTER("hp_extract_record");
+
+#if !defined(DBUG_OFF) && defined(EXTRA_HEAP_DEBUG)
+  if (share->recordspace.is_variable_size)
+  {
+    dump_chunk(share, curr_chunk);
+  }
+#endif
+
+  memcpy(record, curr_chunk, (size_t) share->fixed_data_length);
+
+  if (!share->recordspace.is_variable_size)
+  {
+    /* Nothing more to copy */
+    DBUG_RETURN(0);
+  }
+
+  /* Reserve space for rec_offsets and buf_offsets.*/
+  info->blob_offset= init_offset;
+  src_offset= share->fixed_data_length;
+
+  for (i= share->fixed_column_count; i < share->column_count; i++)
+  {
+    uint length, is_null= 0;
+    uchar *to;
+
+    HP_COLUMNDEF *column= share->column_defs + i;
+
+    if (column->null_bit)
+    {
+      if (record[column->null_pos] & column->null_bit)
+      {
+        is_null= 1;
+      }
+    }
+
+    if (is_null)
+    {
+      /* TODO: is memset really needed? */
+      memset(record + column->offset, 0, column->length);
+      continue;
+    }
+
+    to= record + column->offset;
+    if (column->type == MYSQL_TYPE_VARCHAR || column->type == MYSQL_TYPE_BLOB)
+    {
+      uint pack_length, i;
+      uchar *tmp= to;
+
+      pack_length= column->length_bytes;
+
+      for (i= 0; i < pack_length; i++)
+      {
+        if (src_offset == share->recordspace.chunk_dataspace_length)
+        {
+          SWITCH_TO_NEXT_CHUNK_FOR_READ(share, curr_chunk, src_offset);
+        }
+        *to++= curr_chunk[src_offset++];
+      }
+      /*
+        We copy byte-by-byte and then use hp_calc_blob_length to combine bytes
+        in the right order.
+      */
+      length= hp_calc_blob_length(pack_length, tmp);
+
+      if (column->type == MYSQL_TYPE_BLOB && length == 0)
+      {
+        /*
+          Store a zero pointer for zero-length BLOBs because the server
+          relies on that (see Field_blob::val_*().
+        */
+        *(uchar **) to= 0;
+      }
+      else if (column->type == MYSQL_TYPE_BLOB && length > 0)
+      {
+        uint newsize= info->blob_offset + length;
+
+        DBUG_ASSERT(share->blobs > 0);
+        /*
+          Make sure we have enough space in blob_buffer and store the pointer
+          to this blob in record.
+        */
+        if (info->blob_size < newsize)
+        {
+          uchar *ptr;
+          ptr= my_realloc(info->blob_buffer, newsize, MYF(MY_ALLOW_ZERO_PTR));
+          if (ptr == NULL)
+          {
+            DBUG_RETURN(1);
+          }
+
+          if (info->blob_buffer == NULL)
+          {
+            memset(ptr, 0, init_offset);
+          }
+          info->blob_buffer= ptr;
+          info->blob_size= newsize;
+        }
+
+        rec_offsets= (uint *) info->blob_buffer;
+        buf_offsets= rec_offsets + share->blobs;
+
+        rec_offsets[nblobs]= (uint) (to - record);
+        buf_offsets[nblobs]= info->blob_offset;
+        nblobs++;
+
+        /* Change 'to' so blob data is copied into blob_buffer */
+        to= info->blob_buffer + info->blob_offset;
+        info->blob_offset= newsize;
+      }
+    }
+    else
+    {
+      length= column->length;
+    }
+
+    while (length > 0)
+    {
+      uint to_copy;
+
+      to_copy= share->recordspace.chunk_dataspace_length - src_offset;
+      if (to_copy == 0)
+      {
+        SWITCH_TO_NEXT_CHUNK_FOR_READ(share, curr_chunk, src_offset);
+        to_copy= share->recordspace.chunk_dataspace_length;
+      }
+
+      to_copy= min(length, to_copy);
+
+      memcpy(to, curr_chunk + src_offset, (size_t) to_copy);
+      src_offset+= to_copy;
+      to+= to_copy;
+      length-= to_copy;
+    }
+  }
+
+  /* Store pointers to blob data in record */
+  for (i= 0; i < nblobs; i++)
+  {
+    *(uchar **) (record + rec_offsets[i]) = info->blob_buffer + buf_offsets[i];
+  }
+
+  DBUG_RETURN(0);
+}
diff -ruN a/storage/heap/hp_rfirst.c b/storage/heap/hp_rfirst.c
--- a/storage/heap/hp_rfirst.c	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/hp_rfirst.c	2011-06-02 15:38:02.764917001 +0300
@@ -34,7 +34,10 @@
       memcpy(&pos, pos + (*keyinfo->get_key_length)(keyinfo, pos), 
 	     sizeof(uchar*));
       info->current_ptr = pos;
-      memcpy(record, pos, (size_t)share->reclength);
+      if (hp_extract_record(info, record, pos))
+      {
+        DBUG_RETURN(my_errno);
+      }
       /*
         If we're performing index_first on a table that was taken from
         table cache, info->lastkey_len is initialized to previous query.
diff -ruN a/storage/heap/hp_rkey.c b/storage/heap/hp_rkey.c
--- a/storage/heap/hp_rkey.c	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/hp_rkey.c	2011-06-02 15:38:02.764917001 +0300
@@ -66,7 +66,10 @@
     if (!(keyinfo->flag & HA_NOSAME))
       memcpy(info->lastkey, key, (size_t) keyinfo->length);
   }
-  memcpy(record, pos, (size_t) share->reclength);
+  if (hp_extract_record(info, record, pos))
+  {
+    DBUG_RETURN(my_errno);
+  }
   info->update= HA_STATE_AKTIV;
   DBUG_RETURN(0);
 }
diff -ruN a/storage/heap/hp_rlast.c b/storage/heap/hp_rlast.c
--- a/storage/heap/hp_rlast.c	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/hp_rlast.c	2011-06-02 15:38:02.764917001 +0300
@@ -35,7 +35,10 @@
       memcpy(&pos, pos + (*keyinfo->get_key_length)(keyinfo, pos), 
 	     sizeof(uchar*));
       info->current_ptr = pos;
-      memcpy(record, pos, (size_t)share->reclength);
+      if (hp_extract_record(info, record, pos))
+      {
+        DBUG_RETURN(my_errno);
+      }
       info->update = HA_STATE_AKTIV;
     }
     else
diff -ruN a/storage/heap/hp_rnext.c b/storage/heap/hp_rnext.c
--- a/storage/heap/hp_rnext.c	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/hp_rnext.c	2011-06-02 15:38:02.764917001 +0300
@@ -109,7 +109,10 @@
       my_errno=HA_ERR_END_OF_FILE;
     DBUG_RETURN(my_errno);
   }
-  memcpy(record,pos,(size_t) share->reclength);
+  if (hp_extract_record(info, record, pos))
+  {
+    DBUG_RETURN(my_errno);
+  }
   info->update=HA_STATE_AKTIV | HA_STATE_NEXT_FOUND;
   DBUG_RETURN(0);
 }
diff -ruN a/storage/heap/hp_rprev.c b/storage/heap/hp_rprev.c
--- a/storage/heap/hp_rprev.c	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/hp_rprev.c	2011-06-02 15:38:02.764917001 +0300
@@ -77,7 +77,10 @@
       my_errno=HA_ERR_END_OF_FILE;
     DBUG_RETURN(my_errno);
   }
-  memcpy(record,pos,(size_t) share->reclength);
+  if (hp_extract_record(info, record, pos))
+  {
+    DBUG_RETURN(my_errno);
+  }
   info->update=HA_STATE_AKTIV | HA_STATE_PREV_FOUND;
   DBUG_RETURN(0);
 }
diff -ruN a/storage/heap/hp_rrnd.c b/storage/heap/hp_rrnd.c
--- a/storage/heap/hp_rrnd.c	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/hp_rrnd.c	2011-06-02 15:38:02.764917001 +0300
@@ -36,13 +36,18 @@
     info->update= 0;
     DBUG_RETURN(my_errno= HA_ERR_END_OF_FILE);
   }
-  if (!info->current_ptr[share->reclength])
+  if (get_chunk_status(&share->recordspace, info->current_ptr) !=
+      CHUNK_STATUS_ACTIVE)
   {
+    /* treat deleted and linked chunks as deleted */
     info->update= HA_STATE_PREV_FOUND | HA_STATE_NEXT_FOUND;
     DBUG_RETURN(my_errno=HA_ERR_RECORD_DELETED);
   }
   info->update=HA_STATE_PREV_FOUND | HA_STATE_NEXT_FOUND | HA_STATE_AKTIV;
-  memcpy(record,info->current_ptr,(size_t) share->reclength);
+  if (hp_extract_record(info, record, info->current_ptr))
+  {
+    DBUG_RETURN(my_errno);
+  }
   DBUG_PRINT("exit", ("found record at 0x%lx", (long) info->current_ptr));
   info->current_hash_ptr=0;			/* Can't use rnext */
   DBUG_RETURN(0);
@@ -70,17 +75,17 @@
   {
     pos= ++info->current_record;
     if (pos % share->block.records_in_block &&	/* Quick next record */
-	pos < share->records+share->deleted &&
-	(info->update & HA_STATE_PREV_FOUND))
+        pos < share->used_chunk_count + share->deleted_chunk_count &&
+        (info->update & HA_STATE_PREV_FOUND))
     {
-      info->current_ptr+=share->block.recbuffer;
+      info->current_ptr+= share->block.recbufferlen;
       goto end;
     }
   }
   else
     info->current_record=pos;
 
-  if (pos >= share->records+share->deleted)
+  if (pos >= share->used_chunk_count + share->deleted_chunk_count)
   {
     info->update= 0;
     DBUG_RETURN(my_errno= HA_ERR_END_OF_FILE);
@@ -90,13 +95,17 @@
   hp_find_record(info, pos);
 
 end:
-  if (!info->current_ptr[share->reclength])
+  if (GET_CHUNK_STATUS(info, info->current_ptr) != CHUNK_STATUS_ACTIVE)
   {
+    /* treat deleted and linked chunks as deleted */
     info->update= HA_STATE_PREV_FOUND | HA_STATE_NEXT_FOUND;
     DBUG_RETURN(my_errno=HA_ERR_RECORD_DELETED);
   }
   info->update=HA_STATE_PREV_FOUND | HA_STATE_NEXT_FOUND | HA_STATE_AKTIV;
-  memcpy(record,info->current_ptr,(size_t) share->reclength);
+  if (hp_extract_record(info, record, info->current_ptr))
+  {
+    DBUG_RETURN(my_errno);
+  }
   DBUG_PRINT("exit",("found record at 0x%lx",info->current_ptr));
   info->current_hash_ptr=0;			/* Can't use rnext */
   DBUG_RETURN(0);
diff -ruN a/storage/heap/hp_rsame.c b/storage/heap/hp_rsame.c
--- a/storage/heap/hp_rsame.c	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/hp_rsame.c	2011-06-02 15:38:02.764917001 +0300
@@ -31,7 +31,8 @@
   DBUG_ENTER("heap_rsame");
 
   test_active(info);
-  if (info->current_ptr[share->reclength])
+  if (get_chunk_status(&share->recordspace, info->current_ptr) ==
+      CHUNK_STATUS_ACTIVE)
   {
     if (inx < -1 || inx >= (int) share->keys)
     {
@@ -47,9 +48,15 @@
 	DBUG_RETURN(my_errno);
       }
     }
-    memcpy(record,info->current_ptr,(size_t) share->reclength);
+    if (hp_extract_record(info, record, info->current_ptr))
+    {
+      DBUG_RETURN(my_errno);
+    }
     DBUG_RETURN(0);
   }
+
+  /* treat deleted and linked chunks as deleted */
+
   info->update=0;
 
   DBUG_RETURN(my_errno=HA_ERR_RECORD_DELETED);
diff -ruN a/storage/heap/hp_scan.c b/storage/heap/hp_scan.c
--- a/storage/heap/hp_scan.c	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/hp_scan.c	2011-06-02 15:38:02.774917002 +0300
@@ -30,7 +30,6 @@
   info->lastinx= -1;
   info->current_record= (ulong) ~0L;		/* No current record */
   info->update=0;
-  info->next_block=0;
   DBUG_RETURN(0);
 }
 
@@ -41,32 +40,26 @@
   DBUG_ENTER("heap_scan");
 
   pos= ++info->current_record;
-  if (pos < info->next_block)
+  if (pos >= share->recordspace.chunk_count)
   {
-    info->current_ptr+=share->block.recbuffer;
+    info->update= 0;
+    DBUG_RETURN(my_errno= HA_ERR_END_OF_FILE);
   }
-  else
-  {
-    info->next_block+=share->block.records_in_block;
-    if (info->next_block >= share->records+share->deleted)
-    {
-      info->next_block= share->records+share->deleted;
-      if (pos >= info->next_block)
-      {
-	info->update= 0;
-	DBUG_RETURN(my_errno= HA_ERR_END_OF_FILE);
-      }
-    }
-    hp_find_record(info, pos);
-  }
-  if (!info->current_ptr[share->reclength])
+
+  hp_find_record(info, pos);
+
+  if (get_chunk_status(&share->recordspace, info->current_ptr) !=
+      CHUNK_STATUS_ACTIVE)
   {
-    DBUG_PRINT("warning",("Found deleted record"));
+    DBUG_PRINT("warning",("Found deleted record or secondary chunk"));
     info->update= HA_STATE_PREV_FOUND | HA_STATE_NEXT_FOUND;
     DBUG_RETURN(my_errno=HA_ERR_RECORD_DELETED);
   }
   info->update= HA_STATE_PREV_FOUND | HA_STATE_NEXT_FOUND | HA_STATE_AKTIV;
-  memcpy(record,info->current_ptr,(size_t) share->reclength);
+  if (hp_extract_record(info, record, info->current_ptr))
+  {
+    DBUG_RETURN(my_errno);
+  }
   info->current_hash_ptr=0;			/* Can't use read_next */
   DBUG_RETURN(0);
 } /* heap_scan */
diff -ruN a/storage/heap/hp_test1.c b/storage/heap/hp_test1.c
--- a/storage/heap/hp_test1.c	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/hp_test1.c	2011-06-02 15:38:02.774917002 +0300
@@ -22,6 +22,7 @@
 #include <my_global.h>
 #include <my_sys.h>
 #include <m_string.h>
+#include <mysql_com.h>
 #include "heap.h"
 
 static int get_options(int argc, char *argv[]);
@@ -35,6 +36,7 @@
   uchar record[128],key[32];
   const char *filename;
   HP_KEYDEF keyinfo[10];
+  HP_COLUMNDEF columndef[2];
   HA_KEYSEG keyseg[4];
   HP_CREATE_INFO hp_create_info;
   HP_SHARE *tmp_share;
@@ -51,6 +53,10 @@
   hp_create_info.reclength= 30;
   hp_create_info.max_records= (ulong) flag*100000L;
   hp_create_info.min_records= 10UL;
+  hp_create_info.columns= 2;
+  hp_create_info.columndef= columndef;
+  hp_create_info.fixed_key_fieldnr= 30;
+  hp_create_info.fixed_data_size= sizeof(char*) * 2;
 
   keyinfo[0].keysegs=1;
   keyinfo[0].seg=keyseg;
@@ -62,11 +68,20 @@
   keyinfo[0].seg[0].null_bit= 0;
   keyinfo[0].flag = HA_NOSAME;
 
+  memset(columndef, 0, 2 * sizeof(HP_COLUMNDEF));
+  columndef[0].type= MYSQL_TYPE_STRING;
+  columndef[0].offset= 1;
+  columndef[0].length= 6;
+  columndef[1].type= MYSQL_TYPE_STRING;
+  columndef[1].offset= 7;
+  columndef[1].length= 23;
+
   deleted=0;
   bzero((uchar*) flags,sizeof(flags));
 
   printf("- Creating heap-file\n");
-  if (heap_create(filename, &hp_create_info, &tmp_share, &unused) ||
+  if (heap_create(filename, &hp_create_info,
+                  &tmp_share, &unused) ||
       !(file= heap_open(filename, 2)))
     goto err;
   printf("- Writing records:s\n");
diff -ruN a/storage/heap/hp_test2.c b/storage/heap/hp_test2.c
--- a/storage/heap/hp_test2.c	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/hp_test2.c	2011-06-02 15:38:02.774917002 +0300
@@ -18,6 +18,7 @@
 
 #include "heapdef.h"		/* Because of hp_find_block */
 #include <signal.h>
+#include <mysql_com.h>
 
 #define MAX_RECORDS 100000
 #define MAX_KEYS 4
@@ -44,6 +45,7 @@
   register uint i,j;
   uint ant,n1,n2,n3;
   uint write_count,update,opt_delete,check2,dupp_keys,found_key;
+  uint mem_per_keys;
   int error;
   ulong pos;
   unsigned long key_check;
@@ -53,6 +55,7 @@
   HP_SHARE *tmp_share;
   HP_KEYDEF keyinfo[MAX_KEYS];
   HA_KEYSEG keyseg[MAX_KEYS*5];
+  HP_COLUMNDEF columndef[4];
   HEAP_PTR UNINIT_VAR(position);
   HP_CREATE_INFO hp_create_info;
   CHARSET_INFO *cs= &my_charset_latin1;
@@ -65,12 +68,16 @@
   get_options(argc,argv);
 
   bzero(&hp_create_info, sizeof(hp_create_info));
-  hp_create_info.max_table_size= 1024L*1024L;
+  hp_create_info.max_table_size= 1024L*1024L*1024L;
   hp_create_info.keys= keys;
   hp_create_info.keydef= keyinfo;
   hp_create_info.reclength= reclength;
   hp_create_info.max_records= (ulong) flag*100000L;
   hp_create_info.min_records= (ulong) recant/2;
+  hp_create_info.columns= 4;
+  hp_create_info.columndef= columndef;
+  hp_create_info.fixed_key_fieldnr= 4;
+  hp_create_info.fixed_data_size= 39;
 
   write_count=update=opt_delete=0;
   key_check=0;
@@ -118,11 +125,30 @@
   keyinfo[3].seg[0].null_pos=38;
   keyinfo[3].seg[0].charset=cs;
 
+  memset(columndef, 0, 4 * sizeof(HP_COLUMNDEF));
+  columndef[0].type= MYSQL_TYPE_STRING;
+  columndef[0].offset= 0;
+  columndef[0].length= 6;
+  columndef[1].type= MYSQL_TYPE_STRING;
+  columndef[1].offset= 7;
+  columndef[1].length= 6;
+  columndef[2].type= MYSQL_TYPE_STRING;
+  columndef[2].offset= 12;
+  columndef[2].length= 8;
+  columndef[3].type= MYSQL_TYPE_TINY;
+  columndef[3].offset= 37;
+  columndef[3].length= 1;
+  columndef[3].null_bit= 1;
+  columndef[3].null_pos= 38;
+
+  mem_per_keys= (sizeof(char*) * 2) * 4;
+
   bzero((char*) key1,sizeof(key1));
   bzero((char*) key3,sizeof(key3));
 
   printf("- Creating heap-file\n");
-  if (heap_create(filename, &hp_create_info, &tmp_share, &unused) ||
+  if (heap_create(filename, &hp_create_info,
+                  &tmp_share, &unused) ||
       !(file= heap_open(filename, 2)))
     goto err;
   signal(SIGINT,endprog);
diff -ruN a/storage/heap/hp_write.c b/storage/heap/hp_write.c
--- a/storage/heap/hp_write.c	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/hp_write.c	2011-06-02 15:38:02.774917002 +0300
@@ -25,7 +25,6 @@
 #define HIGHFIND 4
 #define HIGHUSED 8
 
-static uchar *next_free_record_pos(HP_SHARE *info);
 static HASH_INFO *hp_find_free_hash(HP_SHARE *info, HP_BLOCK *block,
 				     ulong records);
 
@@ -34,6 +33,8 @@
   HP_KEYDEF *keydef, *end;
   uchar *pos;
   HP_SHARE *share=info->s;
+  uint rec_length, chunk_count;
+
   DBUG_ENTER("heap_write");
 #ifndef DBUG_OFF
   if (info->mode & O_RDONLY)
@@ -41,7 +42,18 @@
     DBUG_RETURN(my_errno=EACCES);
   }
 #endif
-  if (!(pos=next_free_record_pos(share)))
+
+  if ((share->records >= share->max_records && share->max_records) ||
+      (share->recordspace.total_data_length + share->index_length >=
+       share->max_table_size))
+  {
+    my_errno= HA_ERR_RECORD_FILE_FULL;
+    DBUG_RETURN(my_errno);
+  }
+
+  rec_length= hp_get_encoded_data_length(share, record, &chunk_count);
+
+  if (!(pos= hp_allocate_chunkset(&share->recordspace, chunk_count)))
     DBUG_RETURN(my_errno);
   share->changed=1;
 
@@ -52,8 +64,8 @@
       goto err;
   }
 
-  memcpy(pos,record,(size_t) share->reclength);
-  pos[share->reclength]=1;		/* Mark record as not deleted */
+  hp_copy_record_data_to_chunkset(share, record, pos);
+
   if (++share->records == share->blength)
     share->blength+= share->blength;
   info->current_ptr=pos;
@@ -87,10 +99,7 @@
     keydef--;
   } 
 
-  share->deleted++;
-  *((uchar**) pos)=share->del_link;
-  share->del_link=pos;
-  pos[share->reclength]=0;			/* Record deleted */
+  hp_free_chunks(&share->recordspace, pos);
 
   DBUG_RETURN(my_errno);
 } /* heap_write */
@@ -106,7 +115,8 @@
   uint old_allocated;
 
   custom_arg.keyseg= keyinfo->seg;
-  custom_arg.key_length= hp_rb_make_key(keyinfo, info->recbuf, record, recpos);
+  custom_arg.key_length= hp_rb_make_key(keyinfo, info->recbuf, record, recpos,
+                                        FALSE);
   if (keyinfo->flag & HA_NOSAME)
   {
     custom_arg.search_flag= SEARCH_FIND | SEARCH_UPDATE;
@@ -128,42 +138,6 @@
   return 0;
 }
 
-	/* Find where to place new record */
-
-static uchar *next_free_record_pos(HP_SHARE *info)
-{
-  int block_pos;
-  uchar *pos;
-  size_t length;
-  DBUG_ENTER("next_free_record_pos");
-
-  if (info->del_link)
-  {
-    pos=info->del_link;
-    info->del_link= *((uchar**) pos);
-    info->deleted--;
-    DBUG_PRINT("exit",("Used old position: 0x%lx",(long) pos));
-    DBUG_RETURN(pos);
-  }
-  if (!(block_pos=(info->records % info->block.records_in_block)))
-  {
-    if ((info->records > info->max_records && info->max_records) ||
-        (info->data_length + info->index_length >= info->max_table_size))
-    {
-      my_errno=HA_ERR_RECORD_FILE_FULL;
-      DBUG_RETURN(NULL);
-    }
-    if (hp_get_new_block(&info->block,&length))
-      DBUG_RETURN(NULL);
-    info->data_length+=length;
-  }
-  DBUG_PRINT("exit",("Used new position: 0x%lx",
-		     (long) ((uchar*) info->block.level_info[0].last_blocks+
-                             block_pos * info->block.recbuffer)));
-  DBUG_RETURN((uchar*) info->block.level_info[0].last_blocks+
-	      block_pos*info->block.recbuffer);
-}
-
 
 /*
   Write a hash-key to the hash-index
diff -ruN a/storage/heap/hp_update.c b/storage/heap/hp_update.c
--- a/storage/heap/hp_update.c	2011-04-11 13:44:03.000000000 +0300
+++ b/storage/heap/hp_update.c	2011-05-26 09:07:47.605561000 +0300
@@ -17,43 +17,66 @@
 
 #include "heapdef.h"
 
-int heap_update(HP_INFO *info, const uchar *old, const uchar *heap_new)
+int heap_update(HP_INFO *info, const uchar *old_record, const uchar *new_record)
 {
   HP_KEYDEF *keydef, *end, *p_lastinx;
   uchar *pos;
   my_bool auto_key_changed= 0;
   HP_SHARE *share= info->s;
+  uint old_length, new_length;
+  uint old_chunk_count, new_chunk_count;
+
   DBUG_ENTER("heap_update");
 
   test_active(info);
   pos=info->current_ptr;
 
-  if (info->opt_flag & READ_CHECK_USED && hp_rectest(info,old))
+  if (info->opt_flag & READ_CHECK_USED && hp_rectest(info, old_record))
     DBUG_RETURN(my_errno);				/* Record changed */
+
+  old_length = hp_get_encoded_data_length(share, old_record, &old_chunk_count);
+  new_length = hp_get_encoded_data_length(share, new_record, &new_chunk_count);
+
+  if (new_chunk_count > old_chunk_count)
+  {
+    /* extend the old chunkset size as necessary, but do not shrink yet */
+    if (hp_reallocate_chunkset(&share->recordspace, new_chunk_count, pos))
+    {
+      DBUG_RETURN(my_errno); /* Out of memory or table space */
+    }
+  }
+
   if (--(share->records) < share->blength >> 1) share->blength>>= 1;
   share->changed=1;
 
   p_lastinx= share->keydef + info->lastinx;
   for (keydef= share->keydef, end= keydef + share->keys; keydef < end; keydef++)
   {
-    if (hp_rec_key_cmp(keydef, old, heap_new, 0))
+    if (hp_rec_key_cmp(keydef, old_record, new_record, 0))
     {
-      if ((*keydef->delete_key)(info, keydef, old, pos, keydef == p_lastinx) ||
-          (*keydef->write_key)(info, keydef, heap_new, pos))
+      if ((*keydef->delete_key)(info, keydef, old_record, pos,
+                                keydef == p_lastinx) ||
+          (*keydef->write_key)(info, keydef, new_record, pos))
         goto err;
       if (share->auto_key == (uint) (keydef - share->keydef + 1))
         auto_key_changed= 1;
     }
   }
 
-  memcpy(pos,heap_new,(size_t) share->reclength);
+  hp_copy_record_data_to_chunkset(share, new_record, pos);
   if (++(share->records) == share->blength) share->blength+= share->blength;
 
+  if (new_chunk_count < old_chunk_count)
+  {
+    /* Shrink the chunkset to its new size */
+    hp_reallocate_chunkset(&share->recordspace, new_chunk_count, pos);
+  }
+
 #if !defined(DBUG_OFF) && defined(EXTRA_HEAP_DEBUG)
   DBUG_EXECUTE("check_heap",heap_check_heap(info, 0););
 #endif
   if (auto_key_changed)
-    heap_update_auto_increment(info, heap_new);
+    heap_update_auto_increment(info, new_record);
   DBUG_RETURN(0);
 
  err:
@@ -63,7 +86,7 @@
     if (keydef->algorithm == HA_KEY_ALG_BTREE)
     {
       /* we don't need to delete non-inserted key from rb-tree */
-      if ((*keydef->write_key)(info, keydef, old, pos))
+      if ((*keydef->write_key)(info, keydef, old_record, pos))
       {
         if (++(share->records) == share->blength)
 	  share->blength+= share->blength;
@@ -73,10 +96,10 @@
     }
     while (keydef >= share->keydef)
     {
-      if (hp_rec_key_cmp(keydef, old, heap_new, 0))
+      if (hp_rec_key_cmp(keydef, old_record, new_record, 0))
       {
-	if ((*keydef->delete_key)(info, keydef, heap_new, pos, 0) ||
-	    (*keydef->write_key)(info, keydef, old, pos))
+        if ((*keydef->delete_key)(info, keydef, new_record, pos, 0) ||
+            (*keydef->write_key)(info, keydef, old_record, pos))
 	  break;
       }
       keydef--;
@@ -84,5 +107,12 @@
   }
   if (++(share->records) == share->blength)
     share->blength+= share->blength;
+
+  if (new_chunk_count > old_chunk_count)
+  {
+    /* Shrink the chunkset to its original size */
+    hp_reallocate_chunkset(&share->recordspace, old_chunk_count, pos);
+  }
+
   DBUG_RETURN(my_errno);
 } /* heap_update */