mariadb/heap/hp_rfirst.c
svoj@mysql.com/june.mysql.com 84a9e656e0 BUG#30590 - delete from memory table with composite btree primary key
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.
2007-09-13 15:39:16 +05:00

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));
}
}