mirror of
https://github.com/MariaDB/server.git
synced 2025-02-01 19:41:47 +01:00
cf5762b402
DELETE query against memory table with btree index may remove not all matching rows. This happens only when DELETE uses index read method to find matching rows. E.g. for queries like DELETE FROM t1 WHERE a=1. Fixed by reverting fix for BUG9719 and applying proper solution. heap/hp_delete.c: Reverted fix for BUG9719 as it makes queries like DELETE FROM t1 WHERE a=1 to remove not all matching rows (assuming this is memory table and there is btree key over `a`). This happens because we calculate info->lastkey_len in heap_rkey(). When we enter heap_rnext(), info->lastkey_len is 0 (set by hp_rb_delete_key()). We need to preserve info->lastkey_len in this situation, otherwise tree_search_key() will always return smallest value in a tree. heap/hp_rfirst.c: If we're performing index_first on a table that was taken from table cache, info->lastkey_len is initialized to previous query. Thus we set info->lastkey_len to proper value for subsequent heap_rnext() calls. This is needed for DELETE queries only, otherwise this variable is not used. Note that the same workaround may be needed for heap_rlast(), but for now heap_rlast() is never used for DELETE queries. heap/hp_rnext.c: An optimization for DELETE queries that use index_first()/index_next(). Use faster tree_search_edge() instead of tree_search_key(). mysql-test/r/heap_btree.result: A test case for BUG#30590. mysql-test/t/heap_btree.test: A test case for BUG#30590.
72 lines
2.3 KiB
C
72 lines
2.3 KiB
C
/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 2 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program; if not, write to the Free Software
|
|
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
|
|
|
|
#include "heapdef.h"
|
|
|
|
/* Read first record with the current key */
|
|
|
|
int heap_rfirst(HP_INFO *info, byte *record, int inx)
|
|
{
|
|
HP_SHARE *share = info->s;
|
|
HP_KEYDEF *keyinfo = share->keydef + inx;
|
|
|
|
DBUG_ENTER("heap_rfirst");
|
|
info->lastinx= inx;
|
|
if (keyinfo->algorithm == HA_KEY_ALG_BTREE)
|
|
{
|
|
byte *pos;
|
|
|
|
if ((pos = tree_search_edge(&keyinfo->rb_tree, info->parents,
|
|
&info->last_pos, offsetof(TREE_ELEMENT, left))))
|
|
{
|
|
memcpy(&pos, pos + (*keyinfo->get_key_length)(keyinfo, pos),
|
|
sizeof(byte*));
|
|
info->current_ptr = pos;
|
|
memcpy(record, pos, (size_t)share->reclength);
|
|
/*
|
|
If we're performing index_first on a table that was taken from
|
|
table cache, info->lastkey_len is initialized to previous query.
|
|
Thus we set info->lastkey_len to proper value for subsequent
|
|
heap_rnext() calls.
|
|
This is needed for DELETE queries only, otherwise this variable is
|
|
not used.
|
|
Note that the same workaround may be needed for heap_rlast(), but
|
|
for now heap_rlast() is never used for DELETE queries.
|
|
*/
|
|
info->lastkey_len= 0;
|
|
info->update = HA_STATE_AKTIV;
|
|
}
|
|
else
|
|
{
|
|
my_errno = HA_ERR_END_OF_FILE;
|
|
DBUG_RETURN(my_errno);
|
|
}
|
|
DBUG_RETURN(0);
|
|
}
|
|
else
|
|
{
|
|
if (!(info->s->records))
|
|
{
|
|
my_errno=HA_ERR_END_OF_FILE;
|
|
DBUG_RETURN(my_errno);
|
|
}
|
|
DBUG_ASSERT(0); /* TODO fix it */
|
|
info->current_record=0;
|
|
info->current_hash_ptr=0;
|
|
info->update=HA_STATE_PREV_FOUND;
|
|
DBUG_RETURN(heap_rnext(info,record));
|
|
}
|
|
}
|