RESET SESSION, plus related new DDL commands. Patch from Marko Kreen,

reviewed by Neil Conway. This patch adds the following DDL command
variants: RESET SESSION, RESET TEMP, RESET PLANS, CLOSE ALL, and
DEALLOCATE ALL. RESET SESSION is intended for use by connection
pool software and the like, in order to reset a client session
to something close to its initial state.

Note that while most of these command variants can be executed
inside a transaction block (but are not transaction-aware!),
RESET SESSION cannot. While this is inconsistent, it is intended
to catch programmer mistakes: RESET SESSION in an open transaction
block is probably unintended.

7 files changed, 18 insertions, 8 deletions

diff --git a/src/include/catalog/namespace.h b/src/include/catalog/namespace.h
index 18e3157b9e3..456d22f942c 100644
--- a/src/include/catalog/namespace.h
+++ b/src/include/catalog/namespace.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/namespace.h,v 1.45 2007/03/23 19:53:52 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/namespace.h,v 1.46 2007/04/12 06:53:48 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -100,4 +100,6 @@ extern char *namespace_search_path;
 
 extern List *fetch_search_path(bool includeImplicit);
 
+extern void ResetTempTableNamespace(void);
+
 #endif   /* NAMESPACE_H */
diff --git a/src/include/commands/async.h b/src/include/commands/async.h
index a97abf7dd93..c6a84a0133b 100644
--- a/src/include/commands/async.h
+++ b/src/include/commands/async.h
@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/commands/async.h,v 1.34 2007/01/05 22:19:53 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/commands/async.h,v 1.35 2007/04/12 06:53:48 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -19,6 +19,7 @@ extern bool Trace_notify;
 extern void Async_Notify(const char *relname);
 extern void Async_Listen(const char *relname);
 extern void Async_Unlisten(const char *relname);
+extern void Async_UnlistenAll(void);
 
 /* perform (or cancel) outbound notify processing at transaction commit */
 extern void AtCommit_Notify(void);
diff --git a/src/include/commands/prepare.h b/src/include/commands/prepare.h
index 4e27ab3bb39..c12d248971e 100644
--- a/src/include/commands/prepare.h
+++ b/src/include/commands/prepare.h
@@ -6,7 +6,7 @@
  *
  * Copyright (c) 2002-2007, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/include/commands/prepare.h,v 1.25 2007/03/13 00:33:43 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/commands/prepare.h,v 1.26 2007/04/12 06:53:48 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -59,4 +59,6 @@ extern void DropPreparedStatement(const char *stmt_name, bool showError);
 extern TupleDesc FetchPreparedStatementResultDesc(PreparedStatement *stmt);
 extern List *FetchPreparedStatementTargetList(PreparedStatement *stmt);
 
+void DropAllPreparedStatements(void);
+
 #endif   /* PREPARE_H */
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 8552620be3c..bc421e265fc 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.344 2007/04/02 03:49:41 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.345 2007/04/12 06:53:48 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1451,6 +1451,7 @@ typedef struct ClosePortalStmt
 {
 	NodeTag		type;
 	char	   *portalname;		/* name of the portal (cursor) */
+								/* NULL means CLOSE ALL */
 } ClosePortalStmt;
 
 /* ----------------------
@@ -1981,6 +1982,7 @@ typedef struct DeallocateStmt
 {
 	NodeTag		type;
 	char	   *name;			/* The name of the plan to remove */
+								/* NULL means DEALLOCATE ALL */
 } DeallocateStmt;
 
 /*
diff --git a/src/include/utils/guc.h b/src/include/utils/guc.h
index 3efb8618938..e3315c72257 100644
--- a/src/include/utils/guc.h
+++ b/src/include/utils/guc.h
@@ -7,7 +7,7 @@
  * Copyright (c) 2000-2007, PostgreSQL Global Development Group
  * Written by Peter Eisentraut <peter_e@gmx.net>.
  *
- * $PostgreSQL: pgsql/src/include/utils/guc.h,v 1.80 2007/03/06 02:06:15 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/utils/guc.h,v 1.81 2007/04/12 06:53:48 neilc Exp $
  *--------------------------------------------------------------------
  */
 #ifndef GUC_H
@@ -201,7 +201,7 @@ extern int	GetNumConfigOptions(void);
 extern void SetPGVariable(const char *name, List *args, bool is_local);
 extern void GetPGVariable(const char *name, DestReceiver *dest);
 extern TupleDesc GetPGVariableResultDesc(const char *name);
-extern void ResetPGVariable(const char *name);
+extern void ResetPGVariable(const char *name, bool isTopLevel);
 
 extern char *flatten_set_variable_args(const char *name, List *args);
 
diff --git a/src/include/utils/plancache.h b/src/include/utils/plancache.h
index e193238291d..562b369044f 100644
--- a/src/include/utils/plancache.h
+++ b/src/include/utils/plancache.h
@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/utils/plancache.h,v 1.4 2007/03/23 19:53:52 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/utils/plancache.h,v 1.5 2007/04/12 06:53:48 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -105,4 +105,6 @@ extern void ReleaseCachedPlan(CachedPlan *plan, bool useResOwner);
 extern TupleDesc PlanCacheComputeResultDesc(List *stmt_list);
 extern bool HaveCachedPlans(void);
 
+extern void ResetPlanCache(void);
+
 #endif   /* PLANCACHE_H */
diff --git a/src/include/utils/portal.h b/src/include/utils/portal.h
index 47651006a21..4c31e2a121f 100644
--- a/src/include/utils/portal.h
+++ b/src/include/utils/portal.h
@@ -39,7 +39,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/utils/portal.h,v 1.74 2007/03/13 00:33:43 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/utils/portal.h,v 1.75 2007/04/12 06:53:48 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -212,5 +212,6 @@ extern void PortalDefineQuery(Portal portal,
 				  CachedPlan *cplan);
 extern Node *PortalListGetPrimaryStmt(List *stmts);
 extern void PortalCreateHoldStore(Portal portal);
+extern void PortalHashTableDeleteAll(void);
 
 #endif   /* PORTAL_H */