From: Massimo Dal Zotto <dz@cs.unitn.it>

>       these patches define the UNLISTEN sql command. The code already
>       existed but it was unknown to the parser. Now it can be used
>       like the listen command.
>       You must make clean and delete gram.c and parser.h before make.

src/backend/parser/gram.y

@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.25 1998/08/25 15:04:23 thomas Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.26 1998/08/25 21:36:53 scrappy Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -122,7 +122,7 @@ Oid	param_type(int t); /* used in parse_expr.c */
 		CopyStmt, CreateStmt, CreateAsStmt, CreateSeqStmt, DefineStmt, DestroyStmt,
 		ExtendStmt, FetchStmt,	GrantStmt, CreateTrigStmt, DropTrigStmt,
 		CreatePLangStmt, DropPLangStmt,
-		IndexStmt, ListenStmt, LockStmt, OptimizableStmt,
+		IndexStmt, ListenStmt, UnlistenStmt, LockStmt, OptimizableStmt,
 		ProcedureStmt, 	RecipeStmt, RemoveAggrStmt, RemoveOperStmt,
 		RemoveFuncStmt, RemoveStmt,
 		RenameStmt, RevokeStmt, RuleStmt, TransactionStmt, ViewStmt, LoadStmt,
@@ -378,6 +378,7 @@ stmt :	  AddAttrStmt
 		| GrantStmt
 		| IndexStmt
 		| ListenStmt
+		| UnlistenStmt
 		| LockStmt
 		| ProcedureStmt
 		| RecipeStmt
@@ -2039,6 +2040,14 @@ ListenStmt:  LISTEN relation_name
 				}
 ;
 
+UnlistenStmt:  UNLISTEN relation_name
+				{
+					UnlistenStmt *n = makeNode(UnlistenStmt);
+					n->relname = $2;
+					$$ = (Node *)n;
+				}
+;
+
 
 /*****************************************************************************
  *

src/backend/parser/keywords.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/keywords.c,v 1.41 1998/08/25 15:04:24 thomas Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/keywords.c,v 1.42 1998/08/25 21:36:55 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -209,6 +209,7 @@ static ScanKeyword ScanKeywords[] = {
 	{"type", TYPE_P},
 	{"union", UNION},
 	{"unique", UNIQUE},
+	{"unlisten", UNLISTEN},
 	{"until", UNTIL},
 	{"update", UPDATE},
 	{"user", USER},

src/backend/tcop/utility.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/tcop/utility.c,v 1.47 1998/08/25 21:24:09 scrappy Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/tcop/utility.c,v 1.48 1998/08/25 21:36:56 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -594,6 +594,17 @@ ProcessUtility(Node *parsetree,
 			}
 			break;
 
+		case T_UnlistenStmt:
+			{
+				UnlistenStmt *stmt = (UnlistenStmt *) parsetree;
+
+				PS_SET_STATUS( commandTag = "UNLISTEN" );
+				CHECK_IF_ABORTED();
+
+				Async_Unlisten(stmt->relname, MyProcPid);
+			}
+			break;
+
 			/*
 			 * ******************************** dynamic loader ********************************
 			 *

src/bin/psql/psqlHelp.h

@@ -5,7 +5,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: psqlHelp.h,v 1.49 1998/07/26 01:18:09 momjian Exp $
+ * $Id: psqlHelp.h,v 1.50 1998/08/25 21:36:58 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -273,9 +273,9 @@ static struct _helpStruct QL_HELP[] = {
 \t[HAVING having_clause]\n\
 \t[UNION [ALL] SELECT ...];"},
 	{"listen",
-		"listen for notification on a relation",
+		"listen for notification on a relation name",
 	"\
-\tLISTEN class_name"},
+\tLISTEN class_name|\"name\""},
 	{"load",
 		"dynamically load a module",
 	"\
@@ -345,7 +345,11 @@ set R_PLANS TO 'ON'| 'OFF'"},
 	"\
 \tSHOW DateStyle|GEQO|R_PLANS"},
 #endif
-	{"UPDATE",
+	{"unlisten",
+		"unlisten for notification on a relation name",
+	"\
+\tUNLISTEN class_name|\"name\"|\"*\""},
+	{"update",
 		"update tuples",
 	"\
 \tUPDATE class_name SET attr1 = expr1, ...attrN = exprN\n\

src/include/commands/async.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: async.h,v 1.7 1997/09/08 02:35:37 momjian Exp $
+ * $Id: async.h,v 1.8 1998/08/25 21:37:00 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -20,6 +20,7 @@ extern void Async_Notify(char *relname);
 extern void Async_NotifyAtCommit(void);
 extern void Async_NotifyAtAbort(void);
 extern void Async_Listen(char *relname, int pid);
+extern void Async_Unlisten(char *relname, int pid);
 
 extern GlobalMemory notifyContext;
 

src/include/nodes/nodes.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: nodes.h,v 1.27 1998/08/18 00:49:01 scrappy Exp $
+ * $Id: nodes.h,v 1.28 1998/08/25 21:37:02 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -171,6 +171,7 @@ typedef enum NodeTag
 	T_RuleStmt,
 	T_NotifyStmt,
 	T_ListenStmt,
+	T_UnlistenStmt,
 	T_TransactionStmt,
 	T_ViewStmt,
 	T_LoadStmt,

src/include/nodes/parsenodes.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: parsenodes.h,v 1.56 1998/08/25 15:09:31 thomas Exp $
+ * $Id: parsenodes.h,v 1.57 1998/08/25 21:37:04 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -440,6 +440,16 @@ typedef struct ListenStmt
 	char	   *relname;		/* relation to listen on */
 } ListenStmt;
 
+/* ----------------------
+ *		Unlisten Statement
+ * ----------------------
+ */
+typedef struct UnlistenStmt
+{
+	NodeTag		type;
+	char	   *relname;		/* relation to unlisten on */
+} UnlistenStmt;
+
 /* ----------------------
  *		{Begin|Abort|End} Transaction Statement
  * ----------------------

src/interfaces/ecpg/preproc/keywords.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/interfaces/ecpg/preproc/keywords.c,v 1.2 1998/05/18 16:05:00 scrappy Exp $
+ *	  $Header: /cvsroot/pgsql/src/interfaces/ecpg/preproc/keywords.c,v 1.3 1998/08/25 21:37:06 scrappy Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -201,6 +201,7 @@ static ScanKeyword ScanKeywords[] = {
 	{"type", TYPE_P},
 	{"union", UNION},
 	{"unique", UNIQUE},
+	{"unlisten", UNLISTEN},
 	{"until", UNTIL},
 	{"update", UPDATE},
 	{"user", USER},

src/interfaces/ecpg/preproc/preproc.y

@@ -563,7 +563,7 @@ output_statement(char * stmt, int mode)
                 DATABASE, DELIMITERS, DO, EACH, EXPLAIN, EXTEND,
                 FORWARD, FUNCTION, HANDLER,
                 INCREMENT, INDEX, INHERITS, INSTEAD, ISNULL,
-                LANCOMPILER, LISTEN, LOAD, LOCK_P, LOCATION, MAXVALUE, MINVALUE, MOVE,
+                LANCOMPILER, LISTEN, UNLISTEN, LOAD, LOCK_P, LOCATION, MAXVALUE, MINVALUE, MOVE,
                 NEW, NONE, NOTHING, NOTNULL, OIDS, OPERATOR, PROCEDURAL,
                 RECIPE, RENAME, RESET, RETURNS, ROW, RULE,
                 SEQUENCE, SETOF, SHOW, START, STATEMENT, STDIN, STDOUT, TRUSTED,
@@ -723,6 +723,7 @@ stmt:  AddAttrStmt			{ output_statement($1, 0); }
 		| GrantStmt		{ output_statement($1, 0); }
 		| IndexStmt		{ output_statement($1, 0); }
 		| ListenStmt		{ output_statement($1, 0); }
+		| UnlistenStmt		{ output_statement($1, 0); }
 		| LockStmt		{ output_statement($1, 0); }
 		| ProcedureStmt		{ output_statement($1, 0); }
  		| RecipeStmt		{ output_statement($1, 0); }
@@ -2108,6 +2109,12 @@ ListenStmt:  LISTEN relation_name
                                 }
 ;
 
+UnlistenStmt:  UNLISTEN relation_name
+				{
+					$$ = cat2_str(make1_str("unlisten"), $2);
+                                }
+;
+
 /*****************************************************************************
  *
  *              Transactions: