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Fixes for single-page hash index vacuum.

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Clear LH_PAGE_HAS_DEAD_TUPLES during replay, similar to what gets done
for btree.  Update hashdesc.c for xl_hash_vacuum_one_page.

Oversights in commit 6977b8b7f4 spotted
by Amit Kapila.  Patch by Ashutosh Sharma.

Bump WAL version.  The original patch to make hash indexes write-ahead
logged probably should have done this, and the single page vacuuming
patch probably should have done it again, but better late than never.

Discussion: http://postgr.es/m/CAA4eK1Kd=mJ9xreovcsh0qMiAj-QqCphHVQ_Lfau1DR9oVjASQ@mail.gmail.com
This commit is contained in:
Robert Haas
2017-03-20 15:49:09 -04:00
parent bc18126a6b
commit 953477ca35
6 changed files with 48 additions and 3 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
src/backend/access/hash/hash.c
View File

@@ -790,6 +790,7 @@ hashbucketcleanup(Relation rel, Bucket cur_bucket, Buffer bucket_buf,
OffsetNumber deletable[MaxOffsetNumber];
int ndeletable = 0;
bool retain_pin = false;
bool clear_dead_marking = false;
vacuum_delay_point();
@@ -877,11 +878,14 @@ hashbucketcleanup(Relation rel, Bucket cur_bucket, Buffer bucket_buf,
/*
* Let us mark the page as clean if vacuum removes the DEAD tuples
* from an index page. We do this by clearing LH_PAGE_HAS_DEAD_TUPLES
* flag. Clearing this flag is just a hint; replay won't redo this.
* flag.
*/
if (tuples_removed && *tuples_removed > 0 &&
opaque->hasho_flag & LH_PAGE_HAS_DEAD_TUPLES)
{
opaque->hasho_flag &= ~LH_PAGE_HAS_DEAD_TUPLES;
clear_dead_marking = true;
}
MarkBufferDirty(buf);
@@ -891,6 +895,7 @@ hashbucketcleanup(Relation rel, Bucket cur_bucket, Buffer bucket_buf,
xl_hash_delete xlrec;
XLogRecPtr recptr;
xlrec.clear_dead_marking = clear_dead_marking;
xlrec.is_primary_bucket_page = (buf == bucket_buf) ? true : false;
XLogBeginInsert();

21
src/backend/access/hash/hash_xlog.c
View File

@@ -859,6 +859,19 @@ hash_xlog_delete(XLogReaderState *record)
PageIndexMultiDelete(page, unused, unend - unused);
}
/*
* Mark the page as not containing any LP_DEAD items only if
* clear_dead_marking flag is set to true. See comments in
* hashbucketcleanup() for details.
*/
if (xldata->clear_dead_marking)
{
HashPageOpaque pageopaque;
pageopaque = (HashPageOpaque) PageGetSpecialPointer(page);
pageopaque->hasho_flag &= ~LH_PAGE_HAS_DEAD_TUPLES;
}
PageSetLSN(page, lsn);
MarkBufferDirty(deletebuf);
}
@@ -1078,6 +1091,7 @@ hash_xlog_vacuum_one_page(XLogReaderState *record)
Buffer metabuf;
Page page;
XLogRedoAction action;
HashPageOpaque pageopaque;
xldata = (xl_hash_vacuum_one_page *) XLogRecGetData(record);
@@ -1126,6 +1140,13 @@ hash_xlog_vacuum_one_page(XLogReaderState *record)
PageIndexMultiDelete(page, unused, unend - unused);
}
/*
* Mark the page as not containing any LP_DEAD items. See comments
* in _hash_vacuum_one_page() for details.
*/
pageopaque = (HashPageOpaque) PageGetSpecialPointer(page);
pageopaque->hasho_flag &= ~LH_PAGE_HAS_DEAD_TUPLES;
PageSetLSN(page, lsn);
MarkBufferDirty(buffer);
}

8
src/backend/access/hash/hashinsert.c
View File

@@ -374,6 +374,14 @@ _hash_vacuum_one_page(Relation rel, Buffer metabuf, Buffer buf,
PageIndexMultiDelete(page, deletable, ndeletable);
/*
* Mark the page as not containing any LP_DEAD items. This is not
* certainly true (there might be some that have recently been marked,
* but weren't included in our target-item list), but it will almost
* always be true and it doesn't seem worth an additional page scan
* to check it. Remember that LH_PAGE_HAS_DEAD_TUPLES is only a hint
* anyway.
*/
pageopaque = (HashPageOpaque) PageGetSpecialPointer(page);
pageopaque->hasho_flag &= ~LH_PAGE_HAS_DEAD_TUPLES;