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

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(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
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30
src/backend/parser/analyze.c
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@ -6,7 +6,7 @@
* Portions Copyright (c) 1996-2000, PostgreSQL, Inc
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: analyze.c,v 1.164 2000/11/05 01:42:07 tgl Exp $
* $Id: analyze.c,v 1.165 2000/11/08 22:09:58 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -115,7 +115,7 @@ static void
release_pstate_resources(ParseState *pstate)
{
if (pstate->p_target_relation != NULL)
heap_close(pstate->p_target_relation, AccessShareLock);
heap_close(pstate->p_target_relation, NoLock);
pstate->p_target_relation = NULL;
pstate->p_target_rangetblentry = NULL;
}
@ -292,6 +292,7 @@ transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt)
qry->commandType = CMD_DELETE;
/* set up a range table */
lockTargetTable(pstate, stmt->relname);
makeRangeTable(pstate, NIL);
setTargetTable(pstate, stmt->relname, stmt->inh, true);
@ -331,6 +332,13 @@ transformInsertStmt(ParseState *pstate, InsertStmt *stmt)
qry->commandType = CMD_INSERT;
pstate->p_is_insert = true;
/*
* Must get write lock on target table before scanning SELECT,
* else we will grab the wrong kind of initial lock if the target
* table is also mentioned in the SELECT part.
*/
lockTargetTable(pstate, stmt->relname);
/*
* Is it INSERT ... SELECT or INSERT ... VALUES?
*/
@ -1521,6 +1529,16 @@ transformRuleStmt(ParseState *pstate, RuleStmt *stmt)
qry->commandType = CMD_UTILITY;
qry->utilityStmt = (Node *) stmt;
/*
* To avoid deadlock, make sure the first thing we do is grab
* AccessExclusiveLock on the target relation. This will be
* needed by DefineQueryRewrite(), and we don't want to grab a lesser
* lock beforehand. We don't need to hold a refcount on the relcache
* entry, however.
*/
heap_close(heap_openr(stmt->object->relname, AccessExclusiveLock),
NoLock);
/*
* NOTE: 'OLD' must always have a varno equal to 1 and 'NEW'
* equal to 2. Set up their RTEs in the main pstate for use
@ -1727,6 +1745,9 @@ transformSelectStmt(ParseState *pstate, SelectStmt *stmt)
qry->isBinary = FALSE;
}
/* make FOR UPDATE clause available to addRangeTableEntry */
pstate->p_forUpdate = stmt->forUpdate;
/* set up a range table */
makeRangeTable(pstate, stmt->fromClause);
@ -1765,7 +1786,7 @@ transformSelectStmt(ParseState *pstate, SelectStmt *stmt)
qry->rtable = pstate->p_rtable;
qry->jointree = makeFromExpr(pstate->p_joinlist, qual);
if (stmt->forUpdate != NULL)
if (stmt->forUpdate != NIL)
transformForUpdate(qry, stmt->forUpdate);
return qry;
@ -1951,7 +1972,7 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
qry->rtable = pstate->p_rtable;
qry->jointree = makeFromExpr(pstate->p_joinlist, NULL);
if (forUpdate != NULL)
if (forUpdate != NIL)
transformForUpdate(qry, forUpdate);
return qry;
@ -2159,6 +2180,7 @@ transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt)
* used in FROM, we'd fail to notice that it should be marked
* checkForRead as well as checkForWrite. See setTargetTable().
*/
lockTargetTable(pstate, stmt->relname);
makeRangeTable(pstate, stmt->fromClause);
setTargetTable(pstate, stmt->relname, stmt->inh, true);