Added LIMIT/OFFSET functionality including new regression test for it.

Removed CURRENT keyword for rule queries and changed rules regression
accordingly. CURRENT has beed announced to disappear in v6.5.

Jan

src/backend/commands/command.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/Attic/command.c,v 1.36 1999/02/03 21:16:02 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/Attic/command.c,v 1.37 1999/02/08 14:14:08 wieck Exp $
  *
  * NOTES
  *	  The PortalExecutorHeapMemory crap needs to be eliminated
@@ -40,6 +40,7 @@
 #include "utils/portal.h"
 #include "utils/syscache.h"
 #include "miscadmin.h"
+#include "string.h"
 
 /* ----------------
  *		PortalExecutorHeapMemory stuff
@@ -102,6 +103,7 @@ PerformPortalFetch(char *name,
 	int			feature;
 	QueryDesc  *queryDesc;
 	MemoryContext context;
+	Const		limcount;
 
 	/* ----------------
 	 *	sanity checks
@@ -113,6 +115,21 @@ PerformPortalFetch(char *name,
 		return;
 	}
 
+	/* ----------------
+	 *  Create a const node from the given count value
+	 * ----------------
+	 */
+	memset(&limcount, 0, sizeof(limcount));
+	limcount.type       = T_Const;
+	limcount.consttype  = INT4OID;
+	limcount.constlen   = sizeof(int4);
+	limcount.constvalue = (Datum)count;
+	limcount.constisnull    = FALSE;
+	limcount.constbyval = TRUE;
+	limcount.constisset = FALSE;
+	limcount.constiscast    = FALSE;
+
+
 	/* ----------------
 	 *	get the portal from the portal name
 	 * ----------------
@@ -176,7 +193,8 @@ PerformPortalFetch(char *name,
 	PortalExecutorHeapMemory = (MemoryContext)
 		PortalGetHeapMemory(portal);
 
-	ExecutorRun(queryDesc, PortalGetState(portal), feature, count);
+	ExecutorRun(queryDesc, PortalGetState(portal), feature, 
+				(Node *)NULL, (Node *)&limcount);
 
 	if (dest == None)			/* MOVE */
 		pfree(queryDesc);

src/backend/executor/execMain.c

@@ -26,7 +26,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.75 1999/02/07 16:17:11 wieck Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/execMain.c,v 1.76 1999/02/08 14:14:09 wieck Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -60,21 +60,27 @@ void ExecCheckPerms(CmdType operation, int resultRelation, List *rangeTable,
 
 
 /* decls for local routines only used within this module */
-static TupleDesc InitPlan(CmdType operation, Query *parseTree,
-		 Plan *plan, EState *estate);
-static void EndPlan(Plan *plan, EState *estate);
+static TupleDesc InitPlan(CmdType operation,
+						Query *parseTree,
+		 				Plan *plan,
+						EState *estate);
+static void EndPlan(Plan *plan,
+						EState *estate);
 static TupleTableSlot *ExecutePlan(EState *estate, Plan *plan,
-			CmdType operation, int numberTuples, ScanDirection direction,
-			DestReceiver *destfunc);
+						CmdType operation, 
+						int offsetTuples,
+						int numberTuples,
+						ScanDirection direction,
+						DestReceiver *destfunc);
 static void ExecRetrieve(TupleTableSlot *slot,
-						 DestReceiver *destfunc,
-						 EState *estate);
+						DestReceiver *destfunc,
+						EState *estate);
 static void ExecAppend(TupleTableSlot *slot, ItemPointer tupleid,
-		   EState *estate);
+		   				EState *estate);
 static void ExecDelete(TupleTableSlot *slot, ItemPointer tupleid,
-		   EState *estate);
+		   				EState *estate);
 static void ExecReplace(TupleTableSlot *slot, ItemPointer tupleid,
-			EState *estate);
+						EState *estate);
 
 TupleTableSlot *EvalPlanQual(EState *estate, Index rti, ItemPointer tid);
 static TupleTableSlot *EvalPlanQualNext(EState *estate);
@@ -187,13 +193,16 @@ ExecutorStart(QueryDesc *queryDesc, EState *estate)
  * ----------------------------------------------------------------
  */
 TupleTableSlot *
-ExecutorRun(QueryDesc *queryDesc, EState *estate, int feature, int count)
+ExecutorRun(QueryDesc *queryDesc, EState *estate, int feature, 
+					Node *limoffset, Node *limcount)
 {
 	CmdType			operation;
 	Plan		   *plan;
 	TupleTableSlot *result;
 	CommandDest		dest;
 	DestReceiver   *destfunc;
+	int				offset = 0;
+	int				count = 0;
 
 	/******************
 	 *	sanity checks
@@ -222,6 +231,96 @@ ExecutorRun(QueryDesc *queryDesc, EState *estate, int feature, int count)
 	 */
 	(*destfunc->setup) (destfunc, (TupleDesc) NULL);
 
+    /******************
+     *  if given get the offset of the LIMIT clause
+     ******************
+     */
+    if (limoffset != NULL)
+    {
+        Const       *coffset;
+        Param       *poffset;
+        ParamListInfo   paramLI;
+		int	 i;
+ 
+		switch (nodeTag(limoffset))
+		{
+			case T_Const:
+				coffset = (Const *)limoffset;
+				offset = (int)(coffset->constvalue);
+				break;
+ 
+			case T_Param:
+				poffset = (Param *)limoffset;
+				paramLI = estate->es_param_list_info;
+ 
+				if (paramLI == NULL)
+					elog(ERROR, "parameter for limit offset not in executor state");
+				for (i = 0; paramLI[i].kind != PARAM_INVALID; i++)
+				{
+					if (paramLI[i].kind == PARAM_NUM && paramLI[i].id == poffset->paramid)
+						break;
+				}
+				if (paramLI[i].kind == PARAM_INVALID)
+					elog(ERROR, "parameter for limit offset not in executor state");
+				if (paramLI[i].isnull)
+					elog(ERROR, "limit offset cannot be NULL value");
+				offset = (int)(paramLI[i].value);
+ 
+				break;
+ 
+			default:
+				elog(ERROR, "unexpected node type %d as limit offset", nodeTag(limoffset));
+		}
+ 
+		if (offset < 0)
+			elog(ERROR, "limit offset cannot be negative");
+	}
+ 
+	/******************
+	 *  if given get the count of the LIMIT clause
+	 ******************
+	 */
+	if (limcount != NULL)
+	{
+	    Const       *ccount;
+	    Param       *pcount;
+	    ParamListInfo   paramLI;
+	    int     i;
+ 
+	    switch (nodeTag(limcount))
+	    {
+	        case T_Const:
+	            ccount = (Const *)limcount;
+	            count = (int)(ccount->constvalue);
+	            break;
+ 
+	        case T_Param:
+	            pcount = (Param *)limcount;
+	            paramLI = estate->es_param_list_info;
+ 
+	            if (paramLI == NULL)
+	                elog(ERROR, "parameter for limit count not in executor state");
+	            for (i = 0; paramLI[i].kind != PARAM_INVALID; i++)
+	            {
+	                if (paramLI[i].kind == PARAM_NUM && paramLI[i].id == pcount->paramid)
+	                    break;
+	            }
+	            if (paramLI[i].kind == PARAM_INVALID)
+	                elog(ERROR, "parameter for limit count not in executor state");
+	            if (paramLI[i].isnull)
+	                elog(ERROR, "limit count cannot be NULL value");
+	            count = (int)(paramLI[i].value);
+ 
+	            break;
+ 
+	        default:
+	            elog(ERROR, "unexpected node type %d as limit count", nodeTag(limcount));
+	    }
+ 
+	    if (count < 0)
+	        elog(ERROR, "limit count cannot be negative");
+	}
+
 	switch (feature)
 	{
 
@@ -229,7 +328,8 @@ ExecutorRun(QueryDesc *queryDesc, EState *estate, int feature, int count)
 			result = ExecutePlan(estate,
 								 plan,
 								 operation,
-								 ALL_TUPLES,
+								 offset,
+								 count,
 								 ForwardScanDirection,
 								 destfunc);
 			break;
@@ -237,6 +337,7 @@ ExecutorRun(QueryDesc *queryDesc, EState *estate, int feature, int count)
 			result = ExecutePlan(estate,
 								 plan,
 								 operation,
+								 offset,
 								 count,
 								 ForwardScanDirection,
 								 destfunc);
@@ -250,6 +351,7 @@ ExecutorRun(QueryDesc *queryDesc, EState *estate, int feature, int count)
 			result = ExecutePlan(estate,
 								 plan,
 								 operation,
+								 offset,
 								 count,
 								 BackwardScanDirection,
 								 destfunc);
@@ -264,6 +366,7 @@ ExecutorRun(QueryDesc *queryDesc, EState *estate, int feature, int count)
 			result = ExecutePlan(estate,
 								 plan,
 								 operation,
+								 0,
 								 ONE_TUPLE,
 								 ForwardScanDirection,
 								 destfunc);
@@ -784,6 +887,7 @@ static TupleTableSlot *
 ExecutePlan(EState *estate,
 			Plan *plan,
 			CmdType operation,
+			int offsetTuples,
 			int numberTuples,
 			ScanDirection direction,
 			DestReceiver* destfunc)
@@ -845,6 +949,20 @@ lnext:;
 			break;
 		}
 
+		/******************
+		 *  For now we completely execute the plan and skip
+		 *  result tuples if requested by LIMIT offset.
+		 *  Finally we should try to do it in deeper levels
+		 *  if possible (during index scan)
+		 *  - Jan
+		 ******************
+		 */
+		if (offsetTuples > 0)
+		{
+			--offsetTuples;
+			continue;
+		}
+
 		/******************
 		 *		if we have a junk filter, then project a new
 		 *		tuple with the junk removed.

src/backend/executor/functions.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/executor/functions.c,v 1.22 1999/02/03 21:16:12 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/executor/functions.c,v 1.23 1999/02/08 14:14:09 wieck Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -130,6 +130,9 @@ init_execution_state(FunctionCachePtr fcache,
 									 None);
 		estate = CreateExecutorState();
 
+		if (queryTree->limitOffset != NULL || queryTree->limitCount != NULL)
+			elog(ERROR, "LIMIT clause from SQL functions not yet implemented");
+
 		if (nargs > 0)
 		{
 			int			i;
@@ -199,7 +202,7 @@ postquel_getnext(execution_state *es)
 
 	feature = (LAST_POSTQUEL_COMMAND(es)) ? EXEC_RETONE : EXEC_RUN;
 
-	return ExecutorRun(es->qd, es->estate, feature, 0);
+	return ExecutorRun(es->qd, es->estate, feature, (Node *)NULL, (Node *)NULL);
 }
 
 static void

src/backend/executor/spi.c

@@ -3,7 +3,7 @@
  * spi.c--
  *				Server Programming Interface
  *
- * $Id: spi.c,v 1.32 1999/01/27 16:15:20 wieck Exp $
+ * $Id: spi.c,v 1.33 1999/02/08 14:14:10 wieck Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -779,6 +779,8 @@ _SPI_pquery(QueryDesc *queryDesc, EState *state, int tcount)
 	bool		isRetrieveIntoRelation = false;
 	char	   *intoName = NULL;
 	int			res;
+	Const		tcount_const;
+	Node		*count = NULL;
 
 	switch (operation)
 	{
@@ -813,6 +815,39 @@ _SPI_pquery(QueryDesc *queryDesc, EState *state, int tcount)
 			return SPI_ERROR_OPUNKNOWN;
 	}
 
+	/* ----------------
+	 * Get the query LIMIT tuple count
+	 * ----------------
+	 */
+	if (parseTree->limitCount != NULL)
+	{
+		/* ----------------
+		 * A limit clause in the parsetree overrides the
+		 * tcount parameter
+		 * ----------------
+		 */
+		count = parseTree->limitCount;
+	}
+	else
+	{
+		/* ----------------
+		 * No LIMIT clause in parsetree. Use a local Const node
+		 * to put tcount into it
+		 * ----------------
+		 */
+		memset(&tcount_const, 0, sizeof(tcount_const));
+		tcount_const.type		   = T_Const;
+		tcount_const.consttype	  = INT4OID;
+		tcount_const.constlen	   = sizeof(int4);
+		tcount_const.constvalue	 = (Datum)tcount;
+		tcount_const.constisnull	= FALSE;
+		tcount_const.constbyval	 = TRUE;
+		tcount_const.constisset	 = FALSE;
+		tcount_const.constiscast	= FALSE;
+ 
+		count = (Node *)&tcount_const;
+	}
+ 
 	if (state == NULL)			/* plan preparation */
 		return res;
 #ifdef SPI_EXECUTOR_STATS
@@ -833,7 +868,7 @@ _SPI_pquery(QueryDesc *queryDesc, EState *state, int tcount)
 		return SPI_OK_CURSOR;
 	}
 
-	ExecutorRun(queryDesc, state, EXEC_FOR, tcount);
+	ExecutorRun(queryDesc, state, EXEC_FOR, parseTree->limitOffset, count);
 
 	_SPI_current->processed = state->es_processed;
 	if (operation == CMD_SELECT && queryDesc->dest == SPI)

src/backend/parser/analyze.c

@@ -5,7 +5,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- *  $Id: analyze.c,v 1.97 1999/02/02 03:44:32 momjian Exp $
+ *  $Id: analyze.c,v 1.98 1999/02/08 14:14:11 wieck Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -205,7 +205,11 @@ transformStmt(ParseState *pstate, Node *parseTree)
 
 		case T_SelectStmt:
 			if (!((SelectStmt *) parseTree)->portalname)
+			{
 				result = transformSelectStmt(pstate, (SelectStmt *) parseTree);
+				result->limitOffset = ((SelectStmt *)parseTree)->limitOffset;
+				result->limitCount = ((SelectStmt *)parseTree)->limitCount;
+			}
 			else
 				result = transformCursorStmt(pstate, (SelectStmt *) parseTree);
 			break;

src/backend/parser/gram.y

@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.53 1999/02/07 19:02:19 wieck Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.54 1999/02/08 14:14:12 wieck Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -48,6 +48,7 @@
 #include "storage/lmgr.h"
 #include "utils/numeric.h"
 #include "parser/analyze.h"
+#include "catalog/pg_type.h"
 
 #ifdef MULTIBYTE
 #include "mb/pg_wchar.h"
@@ -168,7 +169,8 @@ Oid	param_type(int t); /* used in parse_expr.c */
 		sort_clause, sortby_list, index_params, index_list, name_list,
 		from_clause, from_list, opt_array_bounds, nest_array_bounds,
 		expr_list, attrs, res_target_list, res_target_list2,
-		def_list, opt_indirection, group_clause, TriggerFuncArgs
+		def_list, opt_indirection, group_clause, TriggerFuncArgs,
+		opt_select_limit
 
 %type <node>	func_return
 %type <boolean>	set_opt
@@ -197,6 +199,8 @@ Oid	param_type(int t); /* used in parse_expr.c */
 
 %type <ival>	fetch_how_many
 
+%type <node>	select_limit_value, select_offset_value
+
 %type <list>	OptSeqList
 %type <defelt>	OptSeqElem
 
@@ -306,9 +310,10 @@ Oid	param_type(int t); /* used in parse_expr.c */
 		DATABASE, DELIMITERS, DO, EACH, ENCODING, EXPLAIN, EXTEND,
 		FORWARD, FUNCTION, HANDLER,
 		INCREMENT, INDEX, INHERITS, INSTEAD, ISNULL,
-		LANCOMPILER, LISTEN, LOAD, LOCATION, LOCK_P, MAXVALUE, MINVALUE, MOVE,
+		LANCOMPILER, LIMIT, LISTEN, LOAD, LOCATION, LOCK_P,
+		MAXVALUE, MINVALUE, MOVE,
 		NEW, NOCREATEDB, NOCREATEUSER, NONE, NOTHING, NOTIFY, NOTNULL,
-		OIDS, OPERATOR, PASSWORD, PROCEDURAL,
+		OFFSET, OIDS, OPERATOR, PASSWORD, PROCEDURAL,
 		RECIPE, RENAME, RESET, RETURNS, ROW, RULE,
 		SEQUENCE, SERIAL, SETOF, SHOW, START, STATEMENT, STDIN, STDOUT, TRUSTED, 
 		UNLISTEN, UNTIL, VACUUM, VALID, VERBOSE, VERSION
@@ -2731,7 +2736,7 @@ opt_of:  OF columnList
  * 
  * The rule returns a SelectStmt Node having the set operations attached to 
  * unionClause and intersectClause (NIL if no set operations were present) */ 
-SelectStmt:	  select_w_o_sort sort_clause for_update_clause
+SelectStmt:	  select_w_o_sort sort_clause for_update_clause opt_select_limit
 			{
 				/* There were no set operations, so just attach the sortClause */
 				if IsA($1, SelectStmt)
@@ -2739,6 +2744,8 @@ SelectStmt:	  select_w_o_sort sort_clause for_update_clause
 				  SelectStmt *n = (SelectStmt *)$1;
   				  n->sortClause = $2;
 				  n->forUpdate = $3;
+				  n->limitOffset = nth(0, $4);
+				  n->limitCount = nth(1, $4);
 				  $$ = (Node *)n;
                 }
 				/* There were set operations: The root of the operator tree
@@ -2920,6 +2927,84 @@ OptUseOp:  USING Op								{ $$ = $2; }
 		| /*EMPTY*/								{ $$ = "<"; /*default*/ }
 		;
 
+
+opt_select_limit:	LIMIT select_limit_value ',' select_offset_value
+			{ $$ = lappend(lappend(NIL, $4), $2); }
+		| LIMIT select_limit_value OFFSET select_offset_value
+			{ $$ = lappend(lappend(NIL, $4), $2); }
+		| LIMIT select_limit_value
+			{ $$ = lappend(lappend(NIL, NULL), $2); }
+		| OFFSET select_offset_value LIMIT select_limit_value
+			{ $$ = lappend(lappend(NIL, $2), $4); }
+		| OFFSET select_offset_value
+			{ $$ = lappend(lappend(NIL, $2), NULL); }
+		| /* EMPTY */
+			{ $$ = lappend(lappend(NIL, NULL), NULL); }
+		;
+
+select_limit_value:		Iconst
+			{
+				Const	*n = makeNode(Const);
+
+				if ($1 < 1)
+					elog(ERROR, "selection limit must be ALL or a positive integer value > 0");
+
+				n->consttype	= INT4OID;
+				n->constlen		= sizeof(int4);
+				n->constvalue	= (Datum)$1;
+				n->constisnull	= FALSE;
+				n->constbyval	= TRUE;
+				n->constisset	= FALSE;
+				n->constiscast	= FALSE;
+				$$ = (Node *)n;
+			}
+		| ALL
+			{
+				Const	*n = makeNode(Const);
+
+				n->consttype	= INT4OID;
+				n->constlen		= sizeof(int4);
+				n->constvalue	= (Datum)0;
+				n->constisnull	= FALSE;
+				n->constbyval	= TRUE;
+				n->constisset	= FALSE;
+				n->constiscast	= FALSE;
+				$$ = (Node *)n;
+			}
+		| PARAM
+			{
+				Param	*n = makeNode(Param);
+
+				n->paramkind	= PARAM_NUM;
+				n->paramid		= $1;
+				n->paramtype	= INT4OID;
+				$$ = (Node *)n;
+			}
+		;
+
+select_offset_value:	Iconst
+			{
+				Const	*n = makeNode(Const);
+
+				n->consttype	= INT4OID;
+				n->constlen		= sizeof(int4);
+				n->constvalue	= (Datum)$1;
+				n->constisnull	= FALSE;
+				n->constbyval	= TRUE;
+				n->constisset	= FALSE;
+				n->constiscast	= FALSE;
+				$$ = (Node *)n;
+			}
+		| PARAM
+			{
+				Param	*n = makeNode(Param);
+
+				n->paramkind	= PARAM_NUM;
+				n->paramid		= $1;
+				n->paramtype	= INT4OID;
+				$$ = (Node *)n;
+			}
+		;
 /*
  *	jimmy bell-style recursive queries aren't supported in the
  *	current system.

src/backend/parser/keywords.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/keywords.c,v 1.52 1999/02/02 03:44:42 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/keywords.c,v 1.53 1999/02/08 14:14:13 wieck Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -68,9 +68,6 @@ static ScanKeyword ScanKeywords[] = {
 	{"createdb", CREATEDB},
 	{"createuser", CREATEUSER},
 	{"cross", CROSS},
-	{"current", CURRENT},		/* 6.4 to 6.5 is migration time! CURRENT
-								 * will be removed in 6.5! Use OLD keyword
-								 * in rules. Jan */
 	{"current_date", CURRENT_DATE},
 	{"current_time", CURRENT_TIME},
 	{"current_timestamp", CURRENT_TIMESTAMP},
@@ -139,6 +136,7 @@ static ScanKeyword ScanKeywords[] = {
 	{"left", LEFT},
 	{"level", LEVEL},
 	{"like", LIKE},
+	{"limit", LIMIT},
 	{"listen", LISTEN},
 	{"load", LOAD},
 	{"local", LOCAL},
@@ -168,6 +166,7 @@ static ScanKeyword ScanKeywords[] = {
 	{"nullif", NULLIF},
 	{"numeric", NUMERIC},
 	{"of", OF},
+	{"offset", OFFSET},
 	{"oids", OIDS},
 	{"old", CURRENT},
 	{"on", ON},

src/backend/rewrite/rewriteDefine.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteDefine.c,v 1.23 1998/10/06 22:14:14 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteDefine.c,v 1.24 1999/02/08 14:14:13 wieck Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -311,6 +311,12 @@ DefineQueryRewrite(RuleStmt *stmt)
 
 		heap_close(event_relation);
 
+		/*
+		 * LIMIT in view is not supported
+		 */
+		if (query->limitOffset != NULL || query->limitCount != NULL)
+			elog(ERROR, "LIMIT clause not supported in views");
+
 		/*
 		 * ... and finally the rule must be named _RETviewname.
 		 */

src/backend/tcop/pquery.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/tcop/pquery.c,v 1.19 1998/09/02 23:05:34 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/tcop/pquery.c,v 1.20 1999/02/08 14:14:14 wieck Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -40,7 +40,8 @@
 #include "commands/command.h"
 
 static char *CreateOperationTag(int operationType);
-static void ProcessQueryDesc(QueryDesc *queryDesc);
+static void ProcessQueryDesc(QueryDesc *queryDesc, Node *limoffset,
+												   Node *limcount);
 
 
 /* ----------------------------------------------------------------
@@ -205,7 +206,7 @@ ProcessPortal(char *portalName,
  * ----------------------------------------------------------------
  */
 static void
-ProcessQueryDesc(QueryDesc *queryDesc)
+ProcessQueryDesc(QueryDesc *queryDesc, Node *limoffset, Node *limcount)
 {
 	Query	   *parseTree;
 	Plan	   *plan;
@@ -330,7 +331,7 @@ ProcessQueryDesc(QueryDesc *queryDesc)
 	 *	 actually run the plan..
 	 * ----------------
 	 */
-	ExecutorRun(queryDesc, state, EXEC_RUN, 0);
+	ExecutorRun(queryDesc, state, EXEC_RUN, limoffset, limcount);
 
 	/* save infos for EndCommand */
 	UpdateCommandInfo(operation, state->es_lastoid, state->es_processed);
@@ -373,5 +374,6 @@ ProcessQuery(Query *parsetree,
 		print_plan(plan, parsetree);
 	}
 	else
-		ProcessQueryDesc(queryDesc);
+		ProcessQueryDesc(queryDesc, parsetree->limitOffset,
+									parsetree->limitCount);
 }

src/include/executor/executor.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: executor.h,v 1.29 1999/02/07 16:17:12 wieck Exp $
+ * $Id: executor.h,v 1.30 1999/02/08 14:14:18 wieck Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -83,7 +83,8 @@ extern HeapTuple ExecRemoveJunk(JunkFilter *junkfilter, TupleTableSlot *slot);
  * prototypes from functions in execMain.c
  */
 extern TupleDesc ExecutorStart(QueryDesc *queryDesc, EState *estate);
-extern TupleTableSlot *ExecutorRun(QueryDesc *queryDesc, EState *estate, int feature, int count);
+extern TupleTableSlot *ExecutorRun(QueryDesc *queryDesc, EState *estate, 
+							int feature, Node *limoffset, Node *limcount);
 extern void ExecutorEnd(QueryDesc *queryDesc, EState *estate);
 extern void ExecConstraints(char *caller, Relation rel, HeapTuple tuple, 
 											EState *estate);

src/test/regress/expected/limit.out

@@ -0,0 +1,106 @@
+QUERY: SELECT ''::text AS two, unique1, unique2, stringu1
+		FROM onek WHERE unique1 > 50
+		ORDER BY unique1 LIMIT 2;
+two|unique1|unique2|stringu1
+---+-------+-------+--------
+   |     51|     76|ZBAAAA  
+   |     52|    985|ACAAAA  
+(2 rows)
+
+QUERY: SELECT ''::text AS five, unique1, unique2, stringu1
+		FROM onek WHERE unique1 > 60
+		ORDER BY unique1 LIMIT 5;
+five|unique1|unique2|stringu1
+----+-------+-------+--------
+    |     61|    560|JCAAAA  
+    |     62|    633|KCAAAA  
+    |     63|    296|LCAAAA  
+    |     64|    479|MCAAAA  
+    |     65|     64|NCAAAA  
+(5 rows)
+
+QUERY: SELECT ''::text AS two, unique1, unique2, stringu1
+		FROM onek WHERE unique1 > 60 AND unique1 < 63
+		ORDER BY unique1 LIMIT 5;
+two|unique1|unique2|stringu1
+---+-------+-------+--------
+   |     61|    560|JCAAAA  
+   |     62|    633|KCAAAA  
+(2 rows)
+
+QUERY: SELECT ''::text AS three, unique1, unique2, stringu1
+		FROM onek WHERE unique1 > 100
+		ORDER BY unique1 LIMIT 3 OFFSET 20;
+three|unique1|unique2|stringu1
+-----+-------+-------+--------
+     |    121|    700|REAAAA  
+     |    122|    519|SEAAAA  
+     |    123|    777|TEAAAA  
+(3 rows)
+
+QUERY: SELECT ''::text AS zero, unique1, unique2, stringu1
+		FROM onek WHERE unique1 < 50
+		ORDER BY unique1 DESC LIMIT 8 OFFSET 99;
+zero|unique1|unique2|stringu1
+----+-------+-------+--------
+(0 rows)
+
+QUERY: SELECT ''::text AS eleven, unique1, unique2, stringu1
+		FROM onek WHERE unique1 < 50
+		ORDER BY unique1 DESC LIMIT 20 OFFSET 39;
+eleven|unique1|unique2|stringu1
+------+-------+-------+--------
+      |     10|    520|KAAAAA  
+      |      9|     49|JAAAAA  
+      |      8|    653|IAAAAA  
+      |      7|    647|HAAAAA  
+      |      6|    978|GAAAAA  
+      |      5|    541|FAAAAA  
+      |      4|    833|EAAAAA  
+      |      3|    431|DAAAAA  
+      |      2|    326|CAAAAA  
+      |      1|    214|BAAAAA  
+      |      0|    998|AAAAAA  
+(11 rows)
+
+QUERY: SELECT ''::text AS ten, unique1, unique2, stringu1
+		FROM onek
+		ORDER BY unique1 OFFSET 990;
+ten|unique1|unique2|stringu1
+---+-------+-------+--------
+   |    990|    369|CMAAAA  
+   |    991|    426|DMAAAA  
+   |    992|    363|EMAAAA  
+   |    993|    661|FMAAAA  
+   |    994|    695|GMAAAA  
+   |    995|    144|HMAAAA  
+   |    996|    258|IMAAAA  
+   |    997|     21|JMAAAA  
+   |    998|    549|KMAAAA  
+   |    999|    152|LMAAAA  
+(10 rows)
+
+QUERY: SELECT ''::text AS five, unique1, unique2, stringu1
+		FROM onek
+		ORDER BY unique1 OFFSET 990 LIMIT 5;
+five|unique1|unique2|stringu1
+----+-------+-------+--------
+    |    990|    369|CMAAAA  
+    |    991|    426|DMAAAA  
+    |    992|    363|EMAAAA  
+    |    993|    661|FMAAAA  
+    |    994|    695|GMAAAA  
+(5 rows)
+
+QUERY: SELECT ''::text AS five, unique1, unique2, stringu1
+		FROM onek
+		ORDER BY unique1 LIMIT 5, 900;
+five|unique1|unique2|stringu1
+----+-------+-------+--------
+    |    900|    913|QIAAAA  
+    |    901|    931|RIAAAA  
+    |    902|    702|SIAAAA  
+    |    903|    641|TIAAAA  
+    |    904|    793|UIAAAA  
+(5 rows)
+

src/test/regress/expected/rules.out

@@ -6,39 +6,39 @@ QUERY: create rule rtest_v1_ins as on insert to rtest_v1 do instead
 	insert into rtest_t1 values (new.a, new.b);
 QUERY: create rule rtest_v1_upd as on update to rtest_v1 do instead
 	update rtest_t1 set a = new.a, b = new.b
-	where a = current.a;
+	where a = old.a;
 QUERY: create rule rtest_v1_del as on delete to rtest_v1 do instead
-	delete from rtest_t1 where a = current.a;
+	delete from rtest_t1 where a = old.a;
 QUERY: create table rtest_system (sysname text, sysdesc text);
 QUERY: create table rtest_interface (sysname text, ifname text);
 QUERY: create table rtest_person (pname text, pdesc text);
 QUERY: create table rtest_admin (pname text, sysname text);
 QUERY: create rule rtest_sys_upd as on update to rtest_system do (
 	update rtest_interface set sysname = new.sysname
-		where sysname = current.sysname;
+		where sysname = old.sysname;
 	update rtest_admin set sysname = new.sysname
-		where sysname = current.sysname
+		where sysname = old.sysname
 	);
 QUERY: create rule rtest_sys_del as on delete to rtest_system do (
-	delete from rtest_interface where sysname = current.sysname;
-	delete from rtest_admin where sysname = current.sysname;
+	delete from rtest_interface where sysname = old.sysname;
+	delete from rtest_admin where sysname = old.sysname;
 	);
 QUERY: create rule rtest_pers_upd as on update to rtest_person do
-	update rtest_admin set pname = new.pname where pname = current.pname;
+	update rtest_admin set pname = new.pname where pname = old.pname;
 QUERY: create rule rtest_pers_del as on delete to rtest_person do
-	delete from rtest_admin where pname = current.pname;
+	delete from rtest_admin where pname = old.pname;
 QUERY: create table rtest_emp (ename char(20), salary money);
 QUERY: create table rtest_emplog (ename char(20), who name, action char(10), newsal money, oldsal money);
 QUERY: create table rtest_empmass (ename char(20), salary money);
 QUERY: create rule rtest_emp_ins as on insert to rtest_emp do
 	insert into rtest_emplog values (new.ename, current_user,
 			'hired', new.salary, '0.00');
-QUERY: create rule rtest_emp_upd as on update to rtest_emp where new.salary != current.salary do
+QUERY: create rule rtest_emp_upd as on update to rtest_emp where new.salary != old.salary do
 	insert into rtest_emplog values (new.ename, current_user,
-			'honored', new.salary, current.salary);
+			'honored', new.salary, old.salary);
 QUERY: create rule rtest_emp_del as on delete to rtest_emp do
-	insert into rtest_emplog values (current.ename, current_user,
-			'fired', '0.00', current.salary);
+	insert into rtest_emplog values (old.ename, current_user,
+			'fired', '0.00', old.salary);
 QUERY: create table rtest_t4 (a int4, b text);
 QUERY: create table rtest_t5 (a int4, b text);
 QUERY: create table rtest_t6 (a int4, b text);
@@ -131,7 +131,7 @@ a| b
 QUERY: delete from rtest_v1 where b = 12;
 QUERY: select * from rtest_v1;
 ** Remember the delete rule on rtest_v1: It says
-** DO INSTEAD DELETE FROM rtest_t1 WHERE a = current.a
+** DO INSTEAD DELETE FROM rtest_t1 WHERE a = old.a
 ** So this time both rows with a = 2 must get deleted
 a| b
 -+--

src/test/regress/sql/limit.sql

@@ -0,0 +1,31 @@
+--
+-- Check the LIMIT/OFFSET feature of SELECT
+--
+
+SELECT ''::text AS two, unique1, unique2, stringu1 
+		FROM onek WHERE unique1 > 50 
+		ORDER BY unique1 LIMIT 2;
+SELECT ''::text AS five, unique1, unique2, stringu1 
+		FROM onek WHERE unique1 > 60 
+		ORDER BY unique1 LIMIT 5;
+SELECT ''::text AS two, unique1, unique2, stringu1 
+		FROM onek WHERE unique1 > 60 AND unique1 < 63
+		ORDER BY unique1 LIMIT 5;
+SELECT ''::text AS three, unique1, unique2, stringu1 
+		FROM onek WHERE unique1 > 100 
+		ORDER BY unique1 LIMIT 3 OFFSET 20;
+SELECT ''::text AS zero, unique1, unique2, stringu1 
+		FROM onek WHERE unique1 < 50 
+		ORDER BY unique1 DESC LIMIT 8 OFFSET 99;
+SELECT ''::text AS eleven, unique1, unique2, stringu1 
+		FROM onek WHERE unique1 < 50 
+		ORDER BY unique1 DESC LIMIT 20 OFFSET 39;
+SELECT ''::text AS ten, unique1, unique2, stringu1 
+		FROM onek
+		ORDER BY unique1 OFFSET 990;
+SELECT ''::text AS five, unique1, unique2, stringu1 
+		FROM onek
+		ORDER BY unique1 OFFSET 990 LIMIT 5;
+SELECT ''::text AS five, unique1, unique2, stringu1 
+		FROM onek
+		ORDER BY unique1 LIMIT 5, 900;

src/test/regress/sql/rules.sql

@@ -16,9 +16,9 @@ create rule rtest_v1_ins as on insert to rtest_v1 do instead
 	insert into rtest_t1 values (new.a, new.b);
 create rule rtest_v1_upd as on update to rtest_v1 do instead
 	update rtest_t1 set a = new.a, b = new.b
-	where a = current.a;
+	where a = old.a;
 create rule rtest_v1_del as on delete to rtest_v1 do instead
-	delete from rtest_t1 where a = current.a;
+	delete from rtest_t1 where a = old.a;
 
 --
 -- Tables and rules for the constraint update/delete test
@@ -35,21 +35,21 @@ create table rtest_admin (pname text, sysname text);
 
 create rule rtest_sys_upd as on update to rtest_system do (
 	update rtest_interface set sysname = new.sysname 
-		where sysname = current.sysname;
+		where sysname = old.sysname;
 	update rtest_admin set sysname = new.sysname 
-		where sysname = current.sysname
+		where sysname = old.sysname
 	);
 
 create rule rtest_sys_del as on delete to rtest_system do (
-	delete from rtest_interface where sysname = current.sysname;
-	delete from rtest_admin where sysname = current.sysname;
+	delete from rtest_interface where sysname = old.sysname;
+	delete from rtest_admin where sysname = old.sysname;
 	);
 
 create rule rtest_pers_upd as on update to rtest_person do 
-	update rtest_admin set pname = new.pname where pname = current.pname;
+	update rtest_admin set pname = new.pname where pname = old.pname;
 
 create rule rtest_pers_del as on delete to rtest_person do 
-	delete from rtest_admin where pname = current.pname;
+	delete from rtest_admin where pname = old.pname;
 
 --
 -- Tables and rules for the logging test
@@ -62,13 +62,13 @@ create rule rtest_emp_ins as on insert to rtest_emp do
 	insert into rtest_emplog values (new.ename, current_user,
 			'hired', new.salary, '0.00');
 
-create rule rtest_emp_upd as on update to rtest_emp where new.salary != current.salary do
+create rule rtest_emp_upd as on update to rtest_emp where new.salary != old.salary do
 	insert into rtest_emplog values (new.ename, current_user,
-			'honored', new.salary, current.salary);
+			'honored', new.salary, old.salary);
 
 create rule rtest_emp_del as on delete to rtest_emp do
-	insert into rtest_emplog values (current.ename, current_user,
-			'fired', '0.00', current.salary);
+	insert into rtest_emplog values (old.ename, current_user,
+			'fired', '0.00', old.salary);
 
 --
 -- Tables and rules for the multiple cascaded qualified instead
@@ -177,7 +177,7 @@ insert into rtest_v1 values (2, 12);
 insert into rtest_v1 values (2, 13);
 select * from rtest_v1;
 ** Remember the delete rule on rtest_v1: It says
-** DO INSTEAD DELETE FROM rtest_t1 WHERE a = current.a
+** DO INSTEAD DELETE FROM rtest_t1 WHERE a = old.a
 ** So this time both rows with a = 2 must get deleted
 \p
 \r

src/test/regress/sql/tests

@@ -62,6 +62,7 @@ select_views
 alter_table
 portals_p2
 rules
+limit
 install_plpgsql
 plpgsql
 temp