Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Commit501c7b9

Browse files
committed
Fix bug in hashbulkdelete.
Commit6d46f47 failed to account forthe possibility that hashbulkdelete() might encounter a bucket thathas been split since it began scanning the bucket array. Repair.Extracted from a larger pathc by Amit Kapila; I rewrote the comment.
1 parenta256650 commit501c7b9

File tree

1 file changed

+19
-3
lines changed

1 file changed

+19
-3
lines changed

‎src/backend/access/hash/hash.c

Lines changed: 19 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -523,7 +523,8 @@ hashbulkdelete(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
523523
orig_maxbucket=metap->hashm_maxbucket;
524524
orig_ntuples=metap->hashm_ntuples;
525525
memcpy(&local_metapage,metap,sizeof(local_metapage));
526-
_hash_relbuf(rel,metabuf);
526+
/* release the lock, but keep pin */
527+
_hash_chgbufaccess(rel,metabuf,HASH_READ,HASH_NOLOCK);
527528

528529
/* Scan the buckets that we know exist */
529530
cur_bucket=0;
@@ -563,8 +564,23 @@ hashbulkdelete(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
563564
*/
564565
if (!H_BUCKET_BEING_SPLIT(bucket_opaque)&&
565566
H_NEEDS_SPLIT_CLEANUP(bucket_opaque))
567+
{
566568
split_cleanup= true;
567569

570+
/*
571+
* This bucket might have been split since we last held a lock on
572+
* the metapage. If so, hashm_maxbucket, hashm_highmask and
573+
* hashm_lowmask might be old enough to cause us to fail to remove
574+
* tuples left behind by the most recent split. To prevent that,
575+
* now that the primary page of the target bucket has been locked
576+
* (and thus can't be further split), update our cached metapage
577+
* data.
578+
*/
579+
_hash_chgbufaccess(rel,metabuf,HASH_NOLOCK,HASH_READ);
580+
memcpy(&local_metapage,metap,sizeof(local_metapage));
581+
_hash_chgbufaccess(rel,metabuf,HASH_READ,HASH_NOLOCK);
582+
}
583+
568584
bucket_buf=buf;
569585

570586
hashbucketcleanup(rel,cur_bucket,bucket_buf,blkno,info->strategy,
@@ -581,15 +597,15 @@ hashbulkdelete(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
581597
}
582598

583599
/* Write-lock metapage and check for split since we started */
584-
metabuf=_hash_getbuf(rel,HASH_METAPAGE,HASH_WRITE,LH_META_PAGE);
600+
_hash_chgbufaccess(rel,metabuf,HASH_NOLOCK,HASH_WRITE);
585601
metap=HashPageGetMeta(BufferGetPage(metabuf));
586602

587603
if (cur_maxbucket!=metap->hashm_maxbucket)
588604
{
589605
/* There's been a split, so process the additional bucket(s) */
590606
cur_maxbucket=metap->hashm_maxbucket;
591607
memcpy(&local_metapage,metap,sizeof(local_metapage));
592-
_hash_relbuf(rel,metabuf);
608+
_hash_chgbufaccess(rel,metabuf,HASH_READ,HASH_NOLOCK);
593609
gotoloop_top;
594610
}
595611

0 commit comments

Comments
 (0)
[8]ページ先頭
©2009-2025 Movatter.jp