diff options
| -rw-r--r-- | src/backend/catalog/index.c | 19 | ||||
| -rw-r--r-- | src/backend/commands/cluster.c | 14 | ||||
| -rw-r--r-- | src/backend/commands/tablecmds.c | 108 | ||||
| -rw-r--r-- | src/include/commands/tablecmds.h | 4 |
4 files changed, 83 insertions, 62 deletions
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c index a8200b105e4..ed30b09b42a 100644 --- a/src/backend/catalog/index.c +++ b/src/backend/catalog/index.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/catalog/index.c,v 1.291 2008/01/14 01:39:09 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/catalog/index.c,v 1.292 2008/01/30 19:46:48 tgl Exp $ * * * INTERFACE ROUTINES @@ -33,11 +33,13 @@ #include "catalog/heap.h" #include "catalog/index.h" #include "catalog/indexing.h" +#include "catalog/namespace.h" #include "catalog/pg_constraint.h" #include "catalog/pg_operator.h" #include "catalog/pg_opclass.h" #include "catalog/pg_tablespace.h" #include "catalog/pg_type.h" +#include "commands/tablecmds.h" #include "executor/executor.h" #include "miscadmin.h" #include "optimizer/clauses.h" @@ -2220,6 +2222,21 @@ reindex_index(Oid indexId) iRel = index_open(indexId, AccessExclusiveLock); /* + * Don't allow reindex on temp tables of other backends ... their local + * buffer manager is not going to cope. + */ + if (isOtherTempNamespace(RelationGetNamespace(iRel))) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("cannot reindex temporary tables of other sessions"))); + + /* + * Also check for active uses of the index in the current transaction; + * we don't want to reindex underneath an open indexscan. + */ + CheckTableNotInUse(iRel, "REINDEX INDEX"); + + /* * If it's a shared index, we must do inplace processing (because we have * no way to update relfilenode in other databases). Otherwise we can do * it the normal transaction-safe way. diff --git a/src/backend/commands/cluster.c b/src/backend/commands/cluster.c index a2a94f1e826..7a9ad8d19a8 100644 --- a/src/backend/commands/cluster.c +++ b/src/backend/commands/cluster.c @@ -11,7 +11,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/commands/cluster.c,v 1.168 2008/01/15 21:20:28 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/commands/cluster.c,v 1.169 2008/01/30 19:46:48 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -30,6 +30,7 @@ #include "catalog/namespace.h" #include "catalog/toasting.h" #include "commands/cluster.h" +#include "commands/tablecmds.h" #include "commands/trigger.h" #include "commands/vacuum.h" #include "miscadmin.h" @@ -459,15 +460,10 @@ check_index_is_clusterable(Relation OldHeap, Oid indexOid, bool recheck) errmsg("cannot cluster temporary tables of other sessions"))); /* - * Also check for pending AFTER trigger events on the relation. We can't - * just leave those be, since they will try to fetch tuples that the - * CLUSTER has moved to new TIDs. + * Also check for active uses of the relation in the current transaction, + * including open scans and pending AFTER trigger events. */ - if (AfterTriggerPendingOnRel(RelationGetRelid(OldHeap))) - ereport(ERROR, - (errcode(ERRCODE_OBJECT_IN_USE), - errmsg("cannot cluster table \"%s\" because it has pending trigger events", - RelationGetRelationName(OldHeap)))); + CheckTableNotInUse(OldHeap, "CLUSTER"); /* Drop relcache refcnt on OldIndex, but keep lock */ index_close(OldIndex, NoLock); diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c index 571990eef9b..3bd0b4d44de 100644 --- a/src/backend/commands/tablecmds.c +++ b/src/backend/commands/tablecmds.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.240 2008/01/17 18:56:54 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.241 2008/01/30 19:46:48 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -194,7 +194,6 @@ static void validateForeignKeyConstraint(FkConstraint *fkconstraint, Relation rel, Relation pkrel, Oid constraintOid); static void createForeignKeyTriggers(Relation rel, FkConstraint *fkconstraint, Oid constraintOid); -static void CheckTableNotInUse(Relation rel); static void ATController(Relation rel, List *cmds, bool recurse); static void ATPrepCmd(List **wqueue, Relation rel, AlterTableCmd *cmd, bool recurse, bool recursing); @@ -681,15 +680,10 @@ truncate_check_rel(Relation rel) errmsg("cannot truncate temporary tables of other sessions"))); /* - * Also check for pending AFTER trigger events on the relation. We can't - * just leave those be, since they will try to fetch tuples that the - * TRUNCATE removes. + * Also check for active uses of the relation in the current transaction, + * including open scans and pending AFTER trigger events. */ - if (AfterTriggerPendingOnRel(RelationGetRelid(rel))) - ereport(ERROR, - (errcode(ERRCODE_OBJECT_IN_USE), - errmsg("cannot truncate table \"%s\" because it has pending trigger events", - RelationGetRelationName(rel)))); + CheckTableNotInUse(rel, "TRUNCATE"); } /*---------- @@ -1729,6 +1723,55 @@ renamerel(Oid myrelid, const char *newrelname, ObjectType reltype) } /* + * Disallow ALTER TABLE (and similar commands) when the current backend has + * any open reference to the target table besides the one just acquired by + * the calling command; this implies there's an open cursor or active plan. + * We need this check because our AccessExclusiveLock doesn't protect us + * against stomping on our own foot, only other people's feet! + * + * For ALTER TABLE, the only case known to cause serious trouble is ALTER + * COLUMN TYPE, and some changes are obviously pretty benign, so this could + * possibly be relaxed to only error out for certain types of alterations. + * But the use-case for allowing any of these things is not obvious, so we + * won't work hard at it for now. + * + * We also reject these commands if there are any pending AFTER trigger events + * for the rel. This is certainly necessary for the rewriting variants of + * ALTER TABLE, because they don't preserve tuple TIDs and so the pending + * events would try to fetch the wrong tuples. It might be overly cautious + * in other cases, but again it seems better to err on the side of paranoia. + * + * REINDEX calls this with "rel" referencing the index to be rebuilt; here + * we are worried about active indexscans on the index. The trigger-event + * check can be skipped, since we are doing no damage to the parent table. + * + * The statement name (eg, "ALTER TABLE") is passed for use in error messages. + */ +void +CheckTableNotInUse(Relation rel, const char *stmt) +{ + int expected_refcnt; + + expected_refcnt = rel->rd_isnailed ? 2 : 1; + if (rel->rd_refcnt != expected_refcnt) + ereport(ERROR, + (errcode(ERRCODE_OBJECT_IN_USE), + /* translator: first %s is a SQL command, eg ALTER TABLE */ + errmsg("cannot %s \"%s\" because " + "it is being used by active queries in this session", + stmt, RelationGetRelationName(rel)))); + + if (rel->rd_rel->relkind != RELKIND_INDEX && + AfterTriggerPendingOnRel(RelationGetRelid(rel))) + ereport(ERROR, + (errcode(ERRCODE_OBJECT_IN_USE), + /* translator: first %s is a SQL command, eg ALTER TABLE */ + errmsg("cannot %s \"%s\" because " + "it has pending trigger events", + stmt, RelationGetRelationName(rel)))); +} + +/* * AlterTable * Execute ALTER TABLE, which can be a list of subcommands * @@ -1766,49 +1809,12 @@ AlterTable(AlterTableStmt *stmt) { Relation rel = relation_openrv(stmt->relation, AccessExclusiveLock); - CheckTableNotInUse(rel); + CheckTableNotInUse(rel, "ALTER TABLE"); ATController(rel, stmt->cmds, interpretInhOption(stmt->relation->inhOpt)); } /* - * Disallow ALTER TABLE when the current backend has any open reference to - * it besides the one we just got (such as an open cursor or active plan); - * our AccessExclusiveLock doesn't protect us against stomping on our own - * foot, only other people's feet! - * - * Note: the only case known to cause serious trouble is ALTER COLUMN TYPE, - * and some changes are obviously pretty benign, so this could possibly be - * relaxed to only error out for certain types of alterations. But the - * use-case for allowing any of these things is not obvious, so we won't - * work hard at it for now. - * - * We also reject ALTER TABLE if there are any pending AFTER trigger events - * for the rel. This is certainly necessary for the rewriting variants of - * ALTER TABLE, because they don't preserve tuple TIDs and so the pending - * events would try to fetch the wrong tuples. It might be overly cautious - * in other cases, but again it seems better to err on the side of paranoia. - */ -static void -CheckTableNotInUse(Relation rel) -{ - int expected_refcnt; - - expected_refcnt = rel->rd_isnailed ? 2 : 1; - if (rel->rd_refcnt != expected_refcnt) - ereport(ERROR, - (errcode(ERRCODE_OBJECT_IN_USE), - errmsg("relation \"%s\" is being used by active queries in this session", - RelationGetRelationName(rel)))); - - if (AfterTriggerPendingOnRel(RelationGetRelid(rel))) - ereport(ERROR, - (errcode(ERRCODE_OBJECT_IN_USE), - errmsg("cannot alter table \"%s\" because it has pending trigger events", - RelationGetRelationName(rel)))); -} - -/* * AlterTableInternal * * ALTER TABLE with target specified by OID @@ -2820,7 +2826,7 @@ ATSimpleRecursion(List **wqueue, Relation rel, if (childrelid == relid) continue; childrel = relation_open(childrelid, AccessExclusiveLock); - CheckTableNotInUse(childrel); + CheckTableNotInUse(childrel, "ALTER TABLE"); ATPrepCmd(wqueue, childrel, cmd, false, true); relation_close(childrel, NoLock); } @@ -2852,7 +2858,7 @@ ATOneLevelRecursion(List **wqueue, Relation rel, Relation childrel; childrel = relation_open(childrelid, AccessExclusiveLock); - CheckTableNotInUse(childrel); + CheckTableNotInUse(childrel, "ALTER TABLE"); ATPrepCmd(wqueue, childrel, cmd, true, true); relation_close(childrel, NoLock); } @@ -3681,7 +3687,7 @@ ATExecDropColumn(Relation rel, const char *colName, Form_pg_attribute childatt; childrel = heap_open(childrelid, AccessExclusiveLock); - CheckTableNotInUse(childrel); + CheckTableNotInUse(childrel, "ALTER TABLE"); tuple = SearchSysCacheCopyAttName(childrelid, colName); if (!HeapTupleIsValid(tuple)) /* shouldn't happen */ diff --git a/src/include/commands/tablecmds.h b/src/include/commands/tablecmds.h index e915fb894c3..e9c965439ce 100644 --- a/src/include/commands/tablecmds.h +++ b/src/include/commands/tablecmds.h @@ -7,7 +7,7 @@ * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group * Portions Copyright (c) 1994, Regents of the University of California * - * $PostgreSQL: pgsql/src/include/commands/tablecmds.h,v 1.36 2008/01/01 19:45:57 momjian Exp $ + * $PostgreSQL: pgsql/src/include/commands/tablecmds.h,v 1.37 2008/01/30 19:46:48 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -34,6 +34,8 @@ extern void AlterRelationNamespaceInternal(Relation classRel, Oid relOid, Oid oldNspOid, Oid newNspOid, bool hasDependEntry); +extern void CheckTableNotInUse(Relation rel, const char *stmt); + extern void ExecuteTruncate(TruncateStmt *stmt); extern void renameatt(Oid myrelid, |