database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-08-27 07:42:10 +03:00
Code Activity

Change the relation_open protocol so that we obtain lock on a relation

Browse Source 
(table or index) before trying to open its relcache entry.  This fixes
race conditions in which someone else commits a change to the relation's
catalog entries while we are in process of doing relcache load.  Problems
of that ilk have been reported sporadically for years, but it was not
really practical to fix until recently --- for instance, the recent
addition of WAL-log support for in-place updates helped.

Along the way, remove pg_am.amconcurrent: all AMs are now expected to support
concurrent update.
This commit is contained in:
Tom Lane
2006-07-31 20:09:10 +00:00
parent 4cd72b53b9
commit 09d3670df3
40 changed files with 635 additions and 648 deletions
Download Patch File Download Diff File Expand all files Collapse all files

31
src/backend/catalog/heap.c
View File

@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/catalog/heap.c,v 1.310 2006/07/31 01:16:36 tgl Exp $
* $PostgreSQL: pgsql/src/backend/catalog/heap.c,v 1.311 2006/07/31 20:09:00 tgl Exp $
*
*
* INTERFACE ROUTINES
@@ -1971,24 +1971,17 @@ RemoveStatistics(Oid relid, AttrNumber attnum)
/*
* RelationTruncateIndexes - truncate all
* indexes associated with the heap relation to zero tuples.
* RelationTruncateIndexes - truncate all indexes associated
* with the heap relation to zero tuples.
*
* The routine will truncate and then reconstruct the indexes on
* the relation specified by the heapId parameter.
* the specified relation. Caller must hold exclusive lock on rel.
*/
static void
RelationTruncateIndexes(Oid heapId)
RelationTruncateIndexes(Relation heapRelation)
{
Relation heapRelation;
ListCell *indlist;
/*
* Open the heap rel. We need grab no lock because we assume
* heap_truncate is holding an exclusive lock on the heap rel.
*/
heapRelation = heap_open(heapId, NoLock);
/* Ask the relcache to produce a list of the indexes of the rel */
foreach(indlist, RelationGetIndexList(heapRelation))
{
@@ -1996,11 +1989,8 @@ RelationTruncateIndexes(Oid heapId)
Relation currentIndex;
IndexInfo *indexInfo;
/* Open the index relation */
currentIndex = index_open(indexId);
/* Obtain exclusive lock on it, just to be sure */
LockRelation(currentIndex, AccessExclusiveLock);
/* Open the index relation; use exclusive lock, just to be sure */
currentIndex = index_open(indexId, AccessExclusiveLock);
/* Fetch info needed for index_build */
indexInfo = BuildIndexInfo(currentIndex);
@@ -2013,11 +2003,8 @@ RelationTruncateIndexes(Oid heapId)
index_build(heapRelation, currentIndex, indexInfo, false);
/* We're done with this index */
index_close(currentIndex);
index_close(currentIndex, NoLock);
}
/* And now done with the heap; but keep lock until commit */
heap_close(heapRelation, NoLock);
}
/*
@@ -2066,7 +2053,7 @@ heap_truncate(List *relids)
RelationTruncate(rel, 0);
/* If this relation has indexes, truncate the indexes too */
RelationTruncateIndexes(RelationGetRelid(rel));
RelationTruncateIndexes(rel);
/*
* Close the relation, but keep exclusive lock on it until commit.