diff options
Diffstat (limited to 'src/backend/parser/analyze.c')
| -rw-r--r-- | src/backend/parser/analyze.c | 30 |
1 files changed, 26 insertions, 4 deletions
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c index 93edc9f8781..63f39f2e4cb 100644 --- a/src/backend/parser/analyze.c +++ b/src/backend/parser/analyze.c @@ -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); @@ -332,6 +333,13 @@ transformInsertStmt(ParseState *pstate, InsertStmt *stmt) 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? */ if (stmt->selectStmt) @@ -1522,6 +1530,16 @@ transformRuleStmt(ParseState *pstate, RuleStmt *stmt) 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 * in parsing the rule qualification. @@ -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); |