database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-06-16 06:01:02 +03:00
Code Activity

Make DROP TABLE rollback-able: postpone physical file delete until commit.

Browse Source 
(WAL logging for this is not done yet, however.)  Clean up a number of really
crufty things that are no longer needed now that DROP behaves nicely.  Make
temp table mapper do the right things when drop or rename affecting a temp
table is rolled back.  Also, remove "relation modified while in use" error
check, in favor of locking tables at first reference and holding that lock
throughout the statement.
This commit is contained in:
Tom Lane
2000-11-08 22:10:03 +00:00
parent ebe0b23690
commit 3908473c80
46 changed files with 1305 additions and 1187 deletions
Download Patch File Download Diff File Expand all files Collapse all files

37
src/backend/parser/parse_clause.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/parser/parse_clause.c,v 1.70 2000/10/07 00:58:17 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/parser/parse_clause.c,v 1.71 2000/11/08 22:09:58 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -87,6 +87,34 @@ makeRangeTable(ParseState *pstate, List *frmList)
}
}
/*
* lockTargetTable
* Find the target relation of INSERT/UPDATE/DELETE and acquire write
* lock on it. This must be done before building the range table,
* in case the target is also mentioned as a source relation --- we
* want to be sure to grab the write lock before any read lock.
*
* The ParseState's link to the target relcache entry is also set here.
*/
void
lockTargetTable(ParseState *pstate, char *relname)
{
/* Close old target; this could only happen for multi-action rules */
if (pstate->p_target_relation != NULL)
heap_close(pstate->p_target_relation, NoLock);
pstate->p_target_relation = NULL;
pstate->p_target_rangetblentry = NULL; /* setTargetTable will set this */
/*
* Open target rel and grab suitable lock (which we will hold till
* end of transaction).
*
* analyze.c will eventually do the corresponding heap_close(),
* but *not* release the lock.
*/
pstate->p_target_relation = heap_openr(relname, RowExclusiveLock);
}
/*
* setTargetTable
* Add the target relation of INSERT/UPDATE/DELETE to the range table,
@ -133,13 +161,10 @@ setTargetTable(ParseState *pstate, char *relname, bool inh, bool inJoinSet)
if (inJoinSet)
addRTEtoJoinList(pstate, rte);
/* This could only happen for multi-action rules */
if (pstate->p_target_relation != NULL)
heap_close(pstate->p_target_relation, AccessShareLock);
/* lockTargetTable should have been called earlier */
Assert(pstate->p_target_relation != NULL);
pstate->p_target_rangetblentry = rte;
pstate->p_target_relation = heap_open(rte->relid, AccessShareLock);
/* will close relation later, see analyze.c */
}