Rename the newly-added commands for discarding session state.

RESET SESSION, RESET PLANS, and RESET TEMP are now DISCARD ALL,
DISCARD PLANS, and DISCARD TEMP, respectively. This is to avoid
confusion with the pre-existing RESET variants: the DISCARD
commands are not actually similar to RESET. Patch from Marko
Kreen, with some minor editorialization.

diff --git a/doc/src/sgml/ref/allfiles.sgml b/doc/src/sgml/ref/allfiles.sgml
index fd1360219e340ae2c33aa2cb6f6e8b50a7cf4d0f..8bfa76aed89576245fc702ed291957bda9557081 100644 (file)
--- a/doc/src/sgml/ref/allfiles.sgml
+++ b/doc/src/sgml/ref/allfiles.sgml
@@ -61,6 +61,7 @@ Complete list of usable sgml source files in this directory.
 <!entity deallocate         system "deallocate.sgml">
 <!entity declare            system "declare.sgml">
 <!entity delete             system "delete.sgml">
+<!entity discard            system "discard.sgml">
 <!entity dropAggregate      system "drop_aggregate.sgml">
 <!entity dropCast           system "drop_cast.sgml">
 <!entity dropConversion     system "drop_conversion.sgml">

diff --git a/doc/src/sgml/ref/discard.sgml b/doc/src/sgml/ref/discard.sgml
new file mode 100644 (file)
index 0000000..d1e1492
--- /dev/null
+++ b/doc/src/sgml/ref/discard.sgml
@@ -0,0 +1,107 @@
+<!--
+$PostgreSQL$
+PostgreSQL documentation
+-->
+
+<refentry id="SQL-DISCARD">
+ <refmeta>
+  <refentrytitle id="SQL-DISCARD-TITLE">DISCARD</refentrytitle>
+  <refmiscinfo>SQL - Language Statements</refmiscinfo>
+ </refmeta>
+
+ <refnamediv>
+  <refname>DISCARD</refname>
+  <refpurpose>Discard internal server state</refpurpose>
+ </refnamediv>
+
+ <indexterm zone="sql-discard">
+  <primary>DISCARD</primary>
+ </indexterm>
+
+ <refsynopsisdiv>
+<synopsis>
+DISCARD { ALL | PLANS | TEMPORARY | TEMP }
+</synopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+  <title>Description</title>
+
+  <para>
+   <command>DISCARD</> releases internal resources associated with a
+   database session. These resources are normally released at the end
+   of the session.
+  </para>
+
+  <para>
+   <command>DISCARD TEMP</> drops all temporary tables created in the
+   current session.  <command>DISCARD PLANS</> releases all internally
+   cached query plans.  <command>DISCARD ALL</> resets a session to
+   its original state, discarding temporary resources and resetting
+   session-local configuration changes.
+  </para>
+ </refsect1>
+
+ <refsect1>
+  <title>Parameters</title>
+
+  <variablelist>
+
+   <varlistentry>
+    <term><literal>TEMPORARY</literal> or <literal>TEMP</literal></term>
+    <listitem>
+     <para>
+      Drops all temporary tables created in the current session.
+     </para>
+    </listitem>
+   </varlistentry>
+
+   <varlistentry>
+    <term><literal>PLANS</literal></term>
+    <listitem>
+     <para>
+      Releases all cached query plans.
+     </para>
+    </listitem>
+   </varlistentry>
+
+   <varlistentry>
+    <term><literal>ALL</literal></term>
+    <listitem>
+     <para>
+      Releases all temporary resources associated with the current
+      session and resets the session to its initial state. This has
+      the same effect as executing the following sequence of
+      statements:
+<programlisting>
+SET SESSION AUTHORIZATION DEFAULT;
+RESET ALL;
+DEALLOCATE ALL;
+CLOSE ALL;
+UNLISTEN *;
+DISCARD PLANS;
+DISCARD TEMP;
+</programlisting>
+     </para>
+    </listitem>
+   </varlistentry>
+
+  </variablelist>
+ </refsect1>
+
+ <refsect1>
+  <title>Notes</title>
+
+   <para>
+    <command>DISCARD ALL</> cannot be executed inside a transaction block.
+   </para>
+ </refsect1>
+
+ <refsect1>
+  <title>Compatibility</title>
+
+  <para>
+   <command>DISCARD</command> is a <productname>PostgreSQL</productname> extension.
+  </para>
+ </refsect1>
+</refentry>

diff --git a/doc/src/sgml/ref/reset.sgml b/doc/src/sgml/ref/reset.sgml
index 544676671e696b6c63ddefa5c4a33a357a9ba1e9..df97f43d349310ee46e76dcbe7e042c13a870604 100644 (file)
--- a/doc/src/sgml/ref/reset.sgml
+++ b/doc/src/sgml/ref/reset.sgml
@@ -22,7 +22,6 @@ PostgreSQL documentation
 <synopsis>
 RESET <replaceable class="PARAMETER">configuration_parameter</replaceable>
 RESET ALL
-RESET { PLANS | SESSION | TEMP | TEMPORARY }
 </synopsis>
  </refsynopsisdiv>
 
@@ -53,15 +52,6 @@ SET <replaceable class="parameter">configuration_parameter</replaceable> TO DEFA
    See the <command>SET</> reference page for details on the
    transaction behavior of <command>RESET</>.
   </para>
-
-  <para>
-   <command>RESET</> can also be used to release internal resources
-   that are usually released at the end of session.  <command>RESET
-   TEMP</> drops all temporary tables created in the current session.
-   <command>RESET PLANS</> releases all internally cached plans.
-   <command>RESET SESSION</> releases all externally visible temporary
-   resources associated with the current session.
-  </para>
  </refsect1>
 
  <refsect1>
@@ -86,56 +76,9 @@ SET <replaceable class="parameter">configuration_parameter</replaceable> TO DEFA
      </para>
     </listitem>
    </varlistentry>
-
-   <varlistentry>
-    <term><literal>TEMP, TEMPORARY</literal></term>
-    <listitem>
-     <para>
-      Drops all temporary tables created in the current session.
-     </para>
-    </listitem>
-   </varlistentry>
-
-   <varlistentry>
-    <term><literal>PLANS</literal></term>
-    <listitem>
-     <para>
-      Releases all cached query plans.
-     </para>
-    </listitem>
-   </varlistentry>
-
-   <varlistentry>
-    <term><literal>SESSION</literal></term>
-    <listitem>
-     <para>
-      Releases all temporary resources associated with the current
-      session. This has the same effect as executing the following
-      command sequence:
-<programlisting>
-SET SESSION AUTHORIZATION DEFAULT;
-RESET ALL;
-DEALLOCATE ALL;
-CLOSE ALL;
-UNLISTEN *;
-RESET PLANS;
-RESET TEMP;
-</programlisting>
-     </para>
-    </listitem>
-   </varlistentry>
-
   </variablelist>
  </refsect1>
 
- <refsect1>
-  <title>Notes</title>
-
-   <para>
-    <command>RESET SESSION</> cannot be executed inside a transaction block.
-   </para>
- </refsect1>
-
  <refsect1>
   <title>Examples</title>
 

diff --git a/doc/src/sgml/reference.sgml b/doc/src/sgml/reference.sgml
index 87ba1e0027b887a92ba24dea7aa924ef47c820f8..dc3f117161d339aafb1f3fb7b159c45955a0b70f 100644 (file)
--- a/doc/src/sgml/reference.sgml
+++ b/doc/src/sgml/reference.sgml
@@ -89,6 +89,7 @@
    &deallocate;
    &declare;
    &delete;
+   &discard;
    &dropAggregate;
    &dropCast;
    &dropConversion;

diff --git a/src/backend/commands/Makefile b/src/backend/commands/Makefile
index 4bf0b965c3aeaa147de60286b92243e2c7c72f4c..4e46d7db96b0a5fb2b86f0b697699db004249e32 100644 (file)
--- a/src/backend/commands/Makefile
+++ b/src/backend/commands/Makefile
@@ -14,7 +14,7 @@ include $(top_builddir)/src/Makefile.global
 
 OBJS = aggregatecmds.o alter.o analyze.o async.o cluster.o comment.o  \
        conversioncmds.o copy.o \
-       dbcommands.o define.o explain.o functioncmds.o \
+       dbcommands.o define.o discard.o explain.o functioncmds.o \
        indexcmds.o lockcmds.o operatorcmds.o opclasscmds.o \
        portalcmds.o prepare.o proclang.o \
        schemacmds.o sequence.o tablecmds.o tablespace.o trigger.o \

diff --git a/src/backend/commands/discard.c b/src/backend/commands/discard.c
new file mode 100644 (file)
index 0000000..3f05361
--- /dev/null
+++ b/src/backend/commands/discard.c
@@ -0,0 +1,71 @@
+/*-------------------------------------------------------------------------
+ *
+ * discard.c
+ *       The implementation of the DISCARD command
+ *
+ * Copyright (c) 1996-2007, PostgreSQL Global Development Group
+ *
+ *
+ * IDENTIFICATION
+ *       $PostgreSQL$
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+
+#include "access/xact.h"
+#include "catalog/namespace.h"
+#include "commands/async.h"
+#include "commands/discard.h"
+#include "commands/prepare.h"
+#include "commands/variable.h"
+#include "utils/plancache.h"
+#include "utils/portal.h"
+
+static void DiscardAll(bool isTopLevel);
+
+/*
+ * DISCARD { ALL | TEMP | PLANS }
+ */
+void
+DiscardCommand(DiscardStmt *stmt, bool isTopLevel)
+{
+       switch (stmt->target)
+       {
+               case DISCARD_ALL:
+                       DiscardAll(isTopLevel);
+                       break;
+
+               case DISCARD_PLANS:
+                       ResetPlanCache();
+                       break;
+
+               case DISCARD_TEMP:
+                       ResetTempTableNamespace();
+                       break;
+
+               default:
+                       elog(ERROR, "unrecognized DISCARD target: %d", stmt->target);
+       }
+}
+
+static void
+DiscardAll(bool isTopLevel)
+{
+       /*
+        * Disallow DISCARD ALL in a transaction block. This is arguably
+        * inconsistent (we don't make a similar check in the command
+        * sequence that DISCARD ALL is equivalent to), but the idea is
+        * to catch mistakes: DISCARD ALL inside a transaction block
+        * would leave the transaction still uncommitted.
+        */
+       PreventTransactionChain(isTopLevel, "DISCARD ALL");
+
+       SetPGVariable("session_authorization", NIL, false);
+       ResetAllOptions();
+       DropAllPreparedStatements();
+       PortalHashTableDeleteAll();
+       Async_UnlistenAll();
+       ResetPlanCache();
+       ResetTempTableNamespace();
+}

diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index 16487133072f807f96a8f12259352f488cc765b8..c516aebd6a5b944a23754c2693e7364923f1b29c 100644 (file)
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -2589,6 +2589,16 @@ _copyVariableResetStmt(VariableResetStmt *from)
        return newnode;
 }
 
+static DiscardStmt *
+_copyDiscardStmt(DiscardStmt *from)
+{
+       DiscardStmt *newnode = makeNode(DiscardStmt);
+
+       COPY_SCALAR_FIELD(target);
+
+       return newnode;
+}
+
 static CreateTableSpaceStmt *
 _copyCreateTableSpaceStmt(CreateTableSpaceStmt *from)
 {
@@ -3380,6 +3390,9 @@ copyObject(void *from)
                case T_VariableResetStmt:
                        retval = _copyVariableResetStmt(from);
                        break;
+               case T_DiscardStmt:
+                       retval = _copyDiscardStmt(from);
+                       break;
                case T_CreateTableSpaceStmt:
                        retval = _copyCreateTableSpaceStmt(from);
                        break;

diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index 0af004ad1d005b5cc216190c045a869c6c3ef8c6..c927159fdd430ad1a27fd6e8ac80c3369f463052 100644 (file)
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -1376,6 +1376,14 @@ _equalVariableResetStmt(VariableResetStmt *a, VariableResetStmt *b)
        return true;
 }
 
+static bool
+_equalDiscardStmt(DiscardStmt *a, DiscardStmt *b)
+{
+       COMPARE_SCALAR_FIELD(target);
+
+       return true;
+}
+
 static bool
 _equalCreateTableSpaceStmt(CreateTableSpaceStmt *a, CreateTableSpaceStmt *b)
 {
@@ -2313,6 +2321,9 @@ equal(void *a, void *b)
                case T_VariableResetStmt:
                        retval = _equalVariableResetStmt(a, b);
                        break;
+               case T_DiscardStmt:
+                       retval = _equalDiscardStmt(a, b);
+                       break;
                case T_CreateTableSpaceStmt:
                        retval = _equalCreateTableSpaceStmt(a, b);
                        break;

diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index bc8006d7ec637c3eae81a7f1834f9e121661574d..686be4d88d4b159f10f43f07e602c8ec3c37cb16 100644 (file)
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -158,7 +158,7 @@ static Node *makeXmlExpr(XmlExprOp op, char *name, List *named_args, List *args)
                CreateOpFamilyStmt AlterOpFamilyStmt CreatePLangStmt
                CreateSchemaStmt CreateSeqStmt CreateStmt CreateTableSpaceStmt
                CreateAssertStmt CreateTrigStmt CreateUserStmt CreateRoleStmt
-               CreatedbStmt DeclareCursorStmt DefineStmt DeleteStmt
+               CreatedbStmt DeclareCursorStmt DefineStmt DeleteStmt DiscardStmt
                DropGroupStmt DropOpClassStmt DropOpFamilyStmt DropPLangStmt DropStmt
                DropAssertStmt DropTrigStmt DropRuleStmt DropCastStmt DropRoleStmt
                DropUserStmt DropdbStmt DropTableSpaceStmt ExplainStmt FetchStmt
@@ -382,7 +382,7 @@ static Node *makeXmlExpr(XmlExprOp op, char *name, List *named_args, List *args)
 
        DATABASE DAY_P DEALLOCATE DEC DECIMAL_P DECLARE DEFAULT DEFAULTS
        DEFERRABLE DEFERRED DEFINER DELETE_P DELIMITER DELIMITERS
-       DESC DISABLE_P DISTINCT DO DOCUMENT_P DOMAIN_P DOUBLE_P DROP
+       DESC DISABLE_P DISCARD DISTINCT DO DOCUMENT_P DOMAIN_P DOUBLE_P DROP
 
        EACH ELSE ENABLE_P ENCODING ENCRYPTED END_P ENUM_P ESCAPE EXCEPT EXCLUDING
        EXCLUSIVE EXECUTE EXISTS EXPLAIN EXTERNAL EXTRACT
@@ -416,7 +416,7 @@ static Node *makeXmlExpr(XmlExprOp op, char *name, List *named_args, List *args)
        OBJECT_P OF OFF OFFSET OIDS OLD ON ONLY OPERATOR OPTION OR
        ORDER OUT_P OUTER_P OVERLAPS OVERLAY OWNED OWNER
 
-       PARTIAL PASSWORD PLACING POSITION
+       PARTIAL PASSWORD PLACING PLANS POSITION
        PRECISION PRESERVE PREPARE PREPARED PRIMARY
        PRIOR PRIVILEGES PROCEDURAL PROCEDURE
 
@@ -569,6 +569,7 @@ stmt :
                        | DeclareCursorStmt
                        | DefineStmt
                        | DeleteStmt
+                       | DiscardStmt
                        | DropAssertStmt
                        | DropCastStmt
                        | DropGroupStmt
@@ -1328,6 +1329,40 @@ CheckPointStmt:
                ;
 
 
+/*****************************************************************************
+ *
+ * DISCARD { ALL | TEMP | PLANS }
+ *
+ *****************************************************************************/
+
+DiscardStmt:
+                       DISCARD ALL
+                               {
+                                       DiscardStmt *n = makeNode(DiscardStmt);
+                                       n->target = DISCARD_ALL;
+                                       $$ = (Node *) n;
+                               }
+                       | DISCARD TEMP
+                               {
+                                       DiscardStmt *n = makeNode(DiscardStmt);
+                                       n->target = DISCARD_TEMP;
+                                       $$ = (Node *) n;
+                               }
+                       | DISCARD TEMPORARY
+                               {
+                                       DiscardStmt *n = makeNode(DiscardStmt);
+                                       n->target = DISCARD_TEMP;
+                                       $$ = (Node *) n;
+                               }
+                       | DISCARD PLANS
+                               {
+                                       DiscardStmt *n = makeNode(DiscardStmt);
+                                       n->target = DISCARD_PLANS;
+                                       $$ = (Node *) n;
+                               }
+               ;
+
+
 /*****************************************************************************
  *
  *     ALTER [ TABLE | INDEX ] variations
@@ -8796,6 +8831,7 @@ unreserved_keyword:
                        | DELIMITER
                        | DELIMITERS
                        | DISABLE_P
+                       | DISCARD
                        | DOCUMENT_P
                        | DOMAIN_P
                        | DOUBLE_P
@@ -8881,6 +8917,7 @@ unreserved_keyword:
                        | OWNER
                        | PARTIAL
                        | PASSWORD
+                       | PLANS
                        | PREPARE
                        | PREPARED
                        | PRESERVE

diff --git a/src/backend/parser/keywords.c b/src/backend/parser/keywords.c
index 6a1ca7f3a84522979f229bccdfc476f8179957ab..a4ecd7303d842fae5f7c453d196c1e48089cecf7 100644 (file)
--- a/src/backend/parser/keywords.c
+++ b/src/backend/parser/keywords.c
@@ -124,6 +124,7 @@ static const ScanKeyword ScanKeywords[] = {
        {"delimiters", DELIMITERS},
        {"desc", DESC},
        {"disable", DISABLE_P},
+       {"discard", DISCARD},
        {"distinct", DISTINCT},
        {"do", DO},
        {"document", DOCUMENT_P},
@@ -269,6 +270,7 @@ static const ScanKeyword ScanKeywords[] = {
        {"partial", PARTIAL},
        {"password", PASSWORD},
        {"placing", PLACING},
+       {"plans", PLANS},
        {"position", POSITION},
        {"precision", PRECISION},
        {"prepare", PREPARE},

diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 26bf62fa93629ac285d9a21f21f321af6e9e32c9..2221083118ecdb105a1c5269f82085cc1b405099 100644 (file)
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -29,6 +29,7 @@
 #include "commands/copy.h"
 #include "commands/dbcommands.h"
 #include "commands/defrem.h"
+#include "commands/discard.h"
 #include "commands/explain.h"
 #include "commands/lockcmds.h"
 #include "commands/portalcmds.h"
@@ -604,10 +605,7 @@ ProcessUtility(Node *parsetree,
                                                        break;
 
                                                case OBJECT_DOMAIN:
-
-                                                       /*
-                                                        * RemoveDomain does its own permissions checks
-                                                        */
+                                                       /* RemoveDomain does its own permissions checks */
                                                        RemoveDomain(names, stmt->behavior,
                                                                                 stmt->missing_ok);
                                                        break;
@@ -618,10 +616,7 @@ ProcessUtility(Node *parsetree,
                                                        break;
 
                                                case OBJECT_SCHEMA:
-
-                                                       /*
-                                                        * RemoveSchema does its own permissions checks
-                                                        */
+                                                       /* RemoveSchema does its own permissions checks */
                                                        RemoveSchema(names, stmt->behavior,
                                                                                 stmt->missing_ok);
                                                        break;
@@ -994,6 +989,10 @@ ProcessUtility(Node *parsetree,
                        }
                        break;
 
+               case T_DiscardStmt:
+                       DiscardCommand((DiscardStmt *) parsetree, isTopLevel);
+                       break;
+
                case T_CreateTrigStmt:
                        CreateTrigger((CreateTrigStmt *) parsetree, InvalidOid);
                        break;
@@ -1752,12 +1751,22 @@ CreateCommandTag(Node *parsetree)
                        break;
 
                case T_VariableResetStmt:
-                       {
-                               VariableResetStmt *stmt = (VariableResetStmt *) parsetree;
-                               if (pg_strcasecmp(stmt->name, "session") == 0)
-                                       tag = "RESET SESSION";
-                               else
-                                       tag = "RESET";
+                       tag = "RESET";
+                       break;
+
+               case T_DiscardStmt:
+                       switch (((DiscardStmt *) parsetree)->target) {
+                               case DISCARD_ALL:
+                                       tag = "DISCARD ALL";
+                                       break;
+                               case DISCARD_PLANS:
+                                       tag = "DISCARD PLANS";
+                                       break;
+                               case DISCARD_TEMP:
+                                       tag = "DISCARD TEMP";
+                                       break;
+                               default:
+                                       tag = "???";
                        }
                        break;
 

diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index fd0abf9e9ff065e9b624878dfc2bf9d35e0c611a..31fbb949fc3cacbbd7b7de18da2eeec2ed5940a4 100644 (file)
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -5047,30 +5047,6 @@ GetPGVariableResultDesc(const char *name)
        return tupdesc;
 }
 
-/*
- * RESET SESSION command.
- */
-static void
-ResetSession(bool isTopLevel)
-{
-       /*
-        * Disallow RESET SESSION in a transaction block. This is arguably
-        * inconsistent (we don't make a similar check in the command
-        * sequence that RESET SESSION is equivalent to), but the idea is
-        * to catch mistakes: RESET SESSION inside a transaction block
-        * would leave the transaction still uncommitted.
-        */
-       PreventTransactionChain(isTopLevel, "RESET SESSION");
-
-       SetPGVariable("session_authorization", NIL, false);
-       ResetAllOptions();
-       DropAllPreparedStatements();
-       PortalHashTableDeleteAll();
-       Async_UnlistenAll();
-       ResetPlanCache();
-       ResetTempTableNamespace();
-}
-
 /*
  * RESET command
  */
@@ -5079,13 +5055,6 @@ ResetPGVariable(const char *name, bool isTopLevel)
 {
        if (pg_strcasecmp(name, "all") == 0)
                ResetAllOptions();
-       else if (pg_strcasecmp(name, "session") == 0)
-               ResetSession(isTopLevel);
-       else if (pg_strcasecmp(name, "temp") == 0 ||
-                        pg_strcasecmp(name, "temporary") == 0)
-               ResetTempTableNamespace();
-       else if (pg_strcasecmp(name, "plans") == 0)
-               ResetPlanCache();
        else
                set_config_option(name,
                                                  NULL,

diff --git a/src/backend/utils/mmgr/portalmem.c b/src/backend/utils/mmgr/portalmem.c
index d4952e51eede3096017900fc60b72cc9477bb91d..40af72e11d866349d41604fa69f00a7af64bc4b6 100644 (file)
--- a/src/backend/utils/mmgr/portalmem.c
+++ b/src/backend/utils/mmgr/portalmem.c
@@ -455,7 +455,7 @@ PortalDrop(Portal portal, bool isTopCommit)
 /*
  * Delete all declared cursors.
  *
- * Used by commands: CLOSE ALL, RESET SESSION
+ * Used by commands: CLOSE ALL, DISCARD ALL
  */
 void
 PortalHashTableDeleteAll(void)

diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index 63c4b0684992d32f1e7241f029f41bf1beab7db9..c3e7daf4062998f74b62f2d00d1ee1c06c3f2805 100644 (file)
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -527,8 +527,8 @@ psql_completion(char *text, int start, int end)
        static const char *const sql_commands[] = {
                "ABORT", "ALTER", "ANALYZE", "BEGIN", "CHECKPOINT", "CLOSE", "CLUSTER",
                "COMMENT", "COMMIT", "COPY", "CREATE", "DEALLOCATE", "DECLARE",
-               "DELETE FROM", "DROP", "END", "EXECUTE", "EXPLAIN", "FETCH", "GRANT",
-               "INSERT", "LISTEN", "LOAD", "LOCK", "MOVE", "NOTIFY", "PREPARE",
+               "DELETE FROM", "DISCARD", "DROP", "END", "EXECUTE", "EXPLAIN", "FETCH",
+               "GRANT", "INSERT", "LISTEN", "LOAD", "LOCK", "MOVE", "NOTIFY", "PREPARE",
                "REASSIGN", "REINDEX", "RELEASE", "RESET", "REVOKE", "ROLLBACK",
                "SAVEPOINT", "SELECT", "SET", "SHOW", "START", "TRUNCATE", "UNLISTEN",
                "UPDATE", "VACUUM", NULL
@@ -1244,6 +1244,15 @@ psql_completion(char *text, int start, int end)
        }
        /* XXX: implement tab completion for DELETE ... USING */
 
+/* DISCARD */
+       else if (pg_strcasecmp(prev_wd, "DISCARD") == 0)
+       {
+               static const char *const list_DISCARD[] =
+               {"ALL", "PLANS", "TEMP", NULL};
+
+               COMPLETE_WITH_LIST(list_DISCARD);
+       }
+
 /* DROP (when not the previous word) */
        /* DROP AGGREGATE */
        else if (pg_strcasecmp(prev3_wd, "DROP") == 0 &&

diff --git a/src/include/commands/discard.h b/src/include/commands/discard.h
new file mode 100644 (file)
index 0000000..6fa5c57
--- /dev/null
+++ b/src/include/commands/discard.h
@@ -0,0 +1,20 @@
+/*-------------------------------------------------------------------------
+ *
+ * discard.h
+ *       prototypes for discard.c.
+ *
+ *
+ * Copyright (c) 1996-2007, PostgreSQL Global Development Group
+ *
+ * $PostgreSQL$
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef DISCARD_H
+#define DISCARD_H
+
+#include "nodes/parsenodes.h"
+
+extern void DiscardCommand(DiscardStmt *stmt, bool isTopLevel);
+
+#endif   /* DISCARD_H */

diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index 0acf89443db716ddf9d695e635ab8c8a64421f8f..ab582dbbf93ef523a31fdd0845f92cfb161fc49f 100644 (file)
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -273,6 +273,7 @@ typedef enum NodeTag
        T_VariableSetStmt,
        T_VariableShowStmt,
        T_VariableResetStmt,
+       T_DiscardStmt,
        T_CreateTrigStmt,
        T_DropPropertyStmt,
        T_CreatePLangStmt,

diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index b287376b9813980219b110e17b27795f61089c05..e6c911929ddcc604089097e45521905efb3b9ecc 100644 (file)
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -1870,6 +1870,24 @@ typedef struct VariableResetStmt
        char       *name;
 } VariableResetStmt;
 
+/* ----------------------
+ * Discard Statement
+ * ----------------------
+ */
+
+typedef enum DiscardMode
+{
+       DISCARD_ALL,
+       DISCARD_PLANS,
+       DISCARD_TEMP
+} DiscardMode;
+
+typedef struct DiscardStmt
+{
+       NodeTag         type;
+       DiscardMode     target;
+} DiscardStmt;
+
 /* ----------------------
  *             LOCK Statement
  * ----------------------

diff --git a/src/test/regress/expected/guc.out b/src/test/regress/expected/guc.out
index 484cc356e7f3486586f59394350a8582d9dbd125..d8ad5667ab7e9efaffd74423980366a02e597491 100644 (file)
--- a/src/test/regress/expected/guc.out
+++ b/src/test/regress/expected/guc.out
@@ -426,7 +426,7 @@ SELECT '2006-08-13 12:34:56'::timestamptz;
 (1 row)
 
 --
--- Test RESET TEMP
+-- Test DISCARD TEMP
 --
 CREATE TEMP TABLE reset_test ( data text ) ON COMMIT DELETE ROWS;
 SELECT relname FROM pg_class WHERE relname = 'reset_test';
@@ -435,14 +435,14 @@ SELECT relname FROM pg_class WHERE relname = 'reset_test';
  reset_test
 (1 row)
 
-RESET TEMP;
+DISCARD TEMP;
 SELECT relname FROM pg_class WHERE relname = 'reset_test';
  relname 
 ---------
 (0 rows)
 
 --
--- Test RESET SESSION
+-- Test DISCARD ALL
 --
 -- do changes
 DECLARE foo CURSOR WITH HOLD FOR SELECT 1;
@@ -489,8 +489,8 @@ SELECT current_user = 'temp_reset_user';
  t
 (1 row)
 
--- big RESET
-RESET SESSION;
+-- discard everything
+DISCARD ALL;
 -- look again
 SELECT relname FROM pg_listener;
  relname 

diff --git a/src/test/regress/sql/guc.sql b/src/test/regress/sql/guc.sql
index 274007a2c33e5935a8172da7cf30464ede67bf6b..a25a13820d73ea839e6700748ba41b9cd8383c29 100644 (file)
--- a/src/test/regress/sql/guc.sql
+++ b/src/test/regress/sql/guc.sql
@@ -125,15 +125,15 @@ SHOW datestyle;
 SELECT '2006-08-13 12:34:56'::timestamptz;
 
 --
--- Test RESET TEMP
+-- Test DISCARD TEMP
 --
 CREATE TEMP TABLE reset_test ( data text ) ON COMMIT DELETE ROWS;
 SELECT relname FROM pg_class WHERE relname = 'reset_test';
-RESET TEMP;
+DISCARD TEMP;
 SELECT relname FROM pg_class WHERE relname = 'reset_test';
 
 --
--- Test RESET SESSION
+-- Test DISCARD ALL
 --
 
 -- do changes
@@ -151,8 +151,8 @@ SELECT name FROM pg_cursors;
 SHOW vacuum_cost_delay;
 SELECT relname from pg_class where relname = 'tmp_foo';
 SELECT current_user = 'temp_reset_user';
--- big RESET
-RESET SESSION;
+-- discard everything
+DISCARD ALL;
 -- look again
 SELECT relname FROM pg_listener;
 SELECT name FROM pg_prepared_statements;