Disallow VACUUM, ANALYZE, TRUNCATE on temp tables belonging to other

backends.  Given that temp tables now store data locally in the local
buffer manager, these things are not going to work safely.

diff --git a/src/backend/catalog/namespace.c b/src/backend/catalog/namespace.c
index 182d9016e974667d3bb407ac1f714935854aaeae..c5a5c70ebc7b898877a6077c6b7d82be89bf7282 100644 (file)
--- a/src/backend/catalog/namespace.c
+++ b/src/backend/catalog/namespace.c
@@ -13,7 +13,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/catalog/namespace.c,v 1.35 2002/09/04 20:31:14 momjian Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/catalog/namespace.c,v 1.36 2002/09/23 20:43:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1217,6 +1217,28 @@ isTempNamespace(Oid namespaceId)
    return false;
 }
 
+/*
+ * isOtherTempNamespace - is the given namespace some other backend's
+ * temporary-table namespace?
+ */
+bool
+isOtherTempNamespace(Oid namespaceId)
+{
+   bool        result;
+   char       *nspname;
+
+   /* If it's my own temp namespace, say "false" */
+   if (isTempNamespace(namespaceId))
+       return false;
+   /* Else, if the namespace name starts with "pg_temp_", say "true" */
+   nspname = get_namespace_name(namespaceId);
+   if (!nspname)
+       return false;           /* no such namespace? */
+   result = (strncmp(nspname, "pg_temp_", 8) == 0);
+   pfree(nspname);
+   return result;
+}
+
 /*
  * PushSpecialNamespace - push a "special" namespace onto the front of the
  * search path.

diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index 5c20b05447e3529158c131080ea93fb935ecf6bd..4c06a28621a93c64ba5ce77c02a87bcd52235876 100644 (file)
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/commands/analyze.c,v 1.46 2002/09/04 20:31:14 momjian Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/commands/analyze.c,v 1.47 2002/09/23 20:43:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -21,6 +21,7 @@
 #include "catalog/catalog.h"
 #include "catalog/catname.h"
 #include "catalog/indexing.h"
+#include "catalog/namespace.h"
 #include "catalog/pg_operator.h"
 #include "catalog/pg_statistic.h"
 #include "catalog/pg_type.h"
@@ -215,6 +216,19 @@ analyze_rel(Oid relid, VacuumStmt *vacstmt)
        return;
    }
 
+   /*
+    * Silently ignore tables that are temp tables of other backends ---
+    * trying to analyze these is rather pointless, since their
+    * contents are probably not up-to-date on disk.  (We don't throw a
+    * warning here; it would just lead to chatter during a database-wide
+    * ANALYZE.)
+    */
+   if (isOtherTempNamespace(RelationGetNamespace(onerel)))
+   {
+       relation_close(onerel, AccessShareLock);
+       return;
+   }
+
    /*
     * We can ANALYZE any table except pg_statistic. See update_attstats
     */

diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index 7b2bab71c34d1e0dc4a0d2878f559799c41d8b95..0934a274c7ad3d76d8707ac48af1b0fea0a84111 100644 (file)
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/commands/tablecmds.c,v 1.43 2002/09/22 19:42:50 tgl Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/commands/tablecmds.c,v 1.44 2002/09/23 20:43:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -367,6 +367,7 @@ TruncateRelation(const RangeVar *relation)
             RelationGetRelationName(rel));
    }
 
+   /* Permissions checks */
    if (!allowSystemTableMods && IsSystemRelation(rel))
        elog(ERROR, "TRUNCATE cannot be used on system tables. '%s' is a system table",
             RelationGetRelationName(rel));
@@ -374,6 +375,13 @@ TruncateRelation(const RangeVar *relation)
    if (!pg_class_ownercheck(relid, GetUserId()))
        aclcheck_error(ACLCHECK_NOT_OWNER, RelationGetRelationName(rel));
 
+   /*
+    * Don't allow truncate on temp tables of other backends ... their
+    * local buffer manager is not going to cope.
+    */
+   if (isOtherTempNamespace(RelationGetNamespace(rel)))
+       elog(ERROR, "TRUNCATE cannot be used on temp tables of other processes");
+
    /*
     * Don't allow truncate on tables which are referenced by foreign keys
     */

diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 42172ac07b49922be6d70135eefddbb4808723bf..04c13be4e074a8380034305727288be9b547493d 100644 (file)
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -13,7 +13,7 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.239 2002/09/23 00:42:48 tgl Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/commands/vacuum.c,v 1.240 2002/09/23 20:43:41 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -775,6 +775,20 @@ vacuum_rel(Oid relid, VacuumStmt *vacstmt, char expected_relkind)
        return;
    }
 
+   /*
+    * Silently ignore tables that are temp tables of other backends ---
+    * trying to vacuum these will lead to great unhappiness, since their
+    * contents are probably not up-to-date on disk.  (We don't throw a
+    * warning here; it would just lead to chatter during a database-wide
+    * VACUUM.)
+    */
+   if (isOtherTempNamespace(RelationGetNamespace(onerel)))
+   {
+       relation_close(onerel, lmode);
+       CommitTransactionCommand(true);
+       return;
+   }
+
    /*
     * Get a session-level lock too. This will protect our access to the
     * relation across multiple transactions, so that we can vacuum the

diff --git a/src/include/catalog/namespace.h b/src/include/catalog/namespace.h
index 3369f678095ad8ef8b899a6f4bc78c1f1f5c7295..531afac1453f7a2144972107713a7a32f02b7b64 100644 (file)
--- a/src/include/catalog/namespace.h
+++ b/src/include/catalog/namespace.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: namespace.h,v 1.20 2002/09/04 20:31:37 momjian Exp $
+ * $Id: namespace.h,v 1.21 2002/09/23 20:43:41 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -76,6 +76,7 @@ extern RangeVar *makeRangeVarFromNameList(List *names);
 extern char *NameListToString(List *names);
 
 extern bool isTempNamespace(Oid namespaceId);
+extern bool isOtherTempNamespace(Oid namespaceId);
 
 extern void PushSpecialNamespace(Oid namespaceId);
 extern void PopSpecialNamespace(Oid namespaceId);