From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sat, 22 Apr 2006 01:26:01 +0000 (+0000)
Subject: Simplify ParamListInfo data structure to support only numbered parameters,
X-Git-Tag: REL8_2_BETA1~1121
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=2206b498d8240447a9353ce4e994ba41a8e307ac;p=thirdparty%2Fpostgresql.git

Simplify ParamListInfo data structure to support only numbered parameters,
not named ones, and replace linear searches of the list with array indexing.
The named-parameter support has been dead code for many years anyway,
and recent profiling suggests that the searching was costing a noticeable
amount of performance for complex queries.
---

diff --git a/src/backend/commands/prepare.c b/src/backend/commands/prepare.c
index c0fbbabdbaa..0892ab9fbb0 100644
--- a/src/backend/commands/prepare.c
+++ b/src/backend/commands/prepare.c
@@ -10,7 +10,7 @@
  * Copyright (c) 2002-2006, PostgreSQL Global Development Group
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/prepare.c,v 1.49 2006/03/05 15:58:24 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/prepare.c,v 1.50 2006/04/22 01:25:58 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -247,30 +247,30 @@ EvaluateParams(EState *estate, List *params, List *argtypes)
 	if (list_length(params) != nargs)
 		elog(ERROR, "wrong number of arguments");
 
+	if (nargs == 0)
+		return NULL;
+
 	exprstates = (List *) ExecPrepareExpr((Expr *) params, estate);
 
-	paramLI = (ParamListInfo)
-		palloc0((nargs + 1) * sizeof(ParamListInfoData));
+	/* sizeof(ParamListInfoData) includes the first array element */
+	paramLI = (ParamListInfo) palloc(sizeof(ParamListInfoData) +
+									 (nargs - 1) * sizeof(ParamExternData));
+	paramLI->numParams = nargs;
 
 	forboth(le, exprstates, la, argtypes)
 	{
 		ExprState  *n = lfirst(le);
-		bool		isNull;
+		ParamExternData *prm = &paramLI->params[i];
 
-		paramLI[i].value = ExecEvalExprSwitchContext(n,
-											  GetPerTupleExprContext(estate),
-													 &isNull,
-													 NULL);
-		paramLI[i].kind = PARAM_NUM;
-		paramLI[i].id = i + 1;
-		paramLI[i].ptype = lfirst_oid(la);
-		paramLI[i].isnull = isNull;
+		prm->ptype = lfirst_oid(la);
+		prm->value = ExecEvalExprSwitchContext(n,
+											   GetPerTupleExprContext(estate),
+											   &prm->isnull,
+											   NULL);
 
 		i++;
 	}
 
-	paramLI[i].kind = PARAM_INVALID;
-
 	return paramLI;
 }
 
diff --git a/src/backend/executor/execQual.c b/src/backend/executor/execQual.c
index fcc7d4b683c..41ea452df58 100644
--- a/src/backend/executor/execQual.c
+++ b/src/backend/executor/execQual.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/execQual.c,v 1.189 2006/03/10 01:51:23 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/execQual.c,v 1.190 2006/04/22 01:25:58 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -605,13 +605,12 @@ ExecEvalParam(ExprState *exprstate, ExprContext *econtext,
 			  bool *isNull, ExprDoneCond *isDone)
 {
 	Param	   *expression = (Param *) exprstate->expr;
-	int			thisParamKind = expression->paramkind;
-	AttrNumber	thisParamId = expression->paramid;
+	int			thisParamId = expression->paramid;
 
 	if (isDone)
 		*isDone = ExprSingleResult;
 
-	if (thisParamKind == PARAM_EXEC)
+	if (expression->paramkind == PARAM_EXEC)
 	{
 		/*
 		 * PARAM_EXEC params (internal executor parameters) are stored in the
@@ -633,18 +632,27 @@ ExecEvalParam(ExprState *exprstate, ExprContext *econtext,
 	else
 	{
 		/*
-		 * All other parameter types must be sought in ecxt_param_list_info.
+		 * PARAM_EXTERN parameters must be sought in ecxt_param_list_info.
 		 */
-		ParamListInfo paramInfo;
-
-		paramInfo = lookupParam(econtext->ecxt_param_list_info,
-								thisParamKind,
-								expression->paramname,
-								thisParamId,
-								false);
-		Assert(paramInfo->ptype == expression->paramtype);
-		*isNull = paramInfo->isnull;
-		return paramInfo->value;
+		ParamListInfo paramInfo = econtext->ecxt_param_list_info;
+
+		Assert(expression->paramkind == PARAM_EXTERN);
+		if (paramInfo &&
+			thisParamId > 0 && thisParamId <= paramInfo->numParams)
+		{
+			ParamExternData *prm = &paramInfo->params[thisParamId - 1];
+
+			if (OidIsValid(prm->ptype))
+			{
+				Assert(prm->ptype == expression->paramtype);
+				*isNull = prm->isnull;
+				return prm->value;
+			}
+		}
+		ereport(ERROR,
+				(errcode(ERRCODE_UNDEFINED_OBJECT),
+				 errmsg("no value found for parameter %d", thisParamId)));
+		return (Datum) 0;		/* keep compiler quiet */
 	}
 }
 
diff --git a/src/backend/executor/functions.c b/src/backend/executor/functions.c
index 0fc4d7b59b2..92e43c1dc57 100644
--- a/src/backend/executor/functions.c
+++ b/src/backend/executor/functions.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/functions.c,v 1.101 2006/03/05 15:58:26 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/functions.c,v 1.102 2006/04/22 01:25:58 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -431,17 +431,19 @@ postquel_sub_params(SQLFunctionCachePtr fcache,
 	{
 		int			i;
 
-		paramLI = (ParamListInfo) palloc0((nargs + 1) * sizeof(ParamListInfoData));
+		/* sizeof(ParamListInfoData) includes the first array element */
+		paramLI = (ParamListInfo) palloc(sizeof(ParamListInfoData) +
+									 (nargs - 1) * sizeof(ParamExternData));
+		paramLI->numParams = nargs;
 
 		for (i = 0; i < nargs; i++)
 		{
-			paramLI[i].kind = PARAM_NUM;
-			paramLI[i].id = i + 1;
-			paramLI[i].ptype = fcache->argtypes[i];
-			paramLI[i].value = fcinfo->arg[i];
-			paramLI[i].isnull = fcinfo->argnull[i];
+			ParamExternData *prm = &paramLI->params[i];
+
+			prm->value = fcinfo->arg[i];
+			prm->isnull = fcinfo->argnull[i];
+			prm->ptype = fcache->argtypes[i];
 		}
-		paramLI[nargs].kind = PARAM_INVALID;
 	}
 	else
 		paramLI = NULL;
diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index 3563ba23d3a..333968676d4 100644
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/spi.c,v 1.150 2006/04/04 19:35:34 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/spi.c,v 1.151 2006/04/22 01:25:58 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -885,19 +885,21 @@ SPI_cursor_open(const char *name, void *plan,
 	/* If the plan has parameters, set them up */
 	if (spiplan->nargs > 0)
 	{
-		paramLI = (ParamListInfo) palloc0((spiplan->nargs + 1) *
-										  sizeof(ParamListInfoData));
+		/* sizeof(ParamListInfoData) includes the first array element */
+		paramLI = (ParamListInfo) palloc(sizeof(ParamListInfoData) +
+							(spiplan->nargs - 1) * sizeof(ParamExternData));
+		paramLI->numParams = spiplan->nargs;
 
 		for (k = 0; k < spiplan->nargs; k++)
 		{
-			paramLI[k].kind = PARAM_NUM;
-			paramLI[k].id = k + 1;
-			paramLI[k].ptype = spiplan->argtypes[k];
-			paramLI[k].isnull = (Nulls && Nulls[k] == 'n');
-			if (paramLI[k].isnull)
+			ParamExternData *prm = &paramLI->params[k];
+
+			prm->ptype = spiplan->argtypes[k];
+			prm->isnull = (Nulls && Nulls[k] == 'n');
+			if (prm->isnull)
 			{
 				/* nulls just copy */
-				paramLI[k].value = Values[k];
+				prm->value = Values[k];
 			}
 			else
 			{
@@ -905,13 +907,11 @@ SPI_cursor_open(const char *name, void *plan,
 				int16		paramTypLen;
 				bool		paramTypByVal;
 
-				get_typlenbyval(spiplan->argtypes[k],
-								&paramTypLen, &paramTypByVal);
-				paramLI[k].value = datumCopy(Values[k],
-											 paramTypByVal, paramTypLen);
+				get_typlenbyval(prm->ptype, &paramTypLen, &paramTypByVal);
+				prm->value = datumCopy(Values[k],
+									   paramTypByVal, paramTypLen);
 			}
 		}
-		paramLI[k].kind = PARAM_INVALID;
 	}
 	else
 		paramLI = NULL;
@@ -1334,18 +1334,19 @@ _SPI_execute_plan(_SPI_plan *plan, Datum *Values, const char *Nulls,
 		{
 			int			k;
 
-			paramLI = (ParamListInfo)
-				palloc0((nargs + 1) * sizeof(ParamListInfoData));
+			/* sizeof(ParamListInfoData) includes the first array element */
+			paramLI = (ParamListInfo) palloc(sizeof(ParamListInfoData) +
+									 (nargs - 1) * sizeof(ParamExternData));
+			paramLI->numParams = nargs;
 
 			for (k = 0; k < nargs; k++)
 			{
-				paramLI[k].kind = PARAM_NUM;
-				paramLI[k].id = k + 1;
-				paramLI[k].ptype = plan->argtypes[k];
-				paramLI[k].isnull = (Nulls && Nulls[k] == 'n');
-				paramLI[k].value = Values[k];
+				ParamExternData *prm = &paramLI->params[k];
+
+				prm->value = Values[k];
+				prm->isnull = (Nulls && Nulls[k] == 'n');
+				prm->ptype = plan->argtypes[k];
 			}
-			paramLI[k].kind = PARAM_INVALID;
 		}
 		else
 			paramLI = NULL;
diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index cd8ebe1f5d6..b060d38b5ed 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -15,7 +15,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/copyfuncs.c,v 1.333 2006/04/15 17:45:34 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/copyfuncs.c,v 1.334 2006/04/22 01:25:58 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -729,7 +729,6 @@ _copyParam(Param *from)
 
 	COPY_SCALAR_FIELD(paramkind);
 	COPY_SCALAR_FIELD(paramid);
-	COPY_STRING_FIELD(paramname);
 	COPY_SCALAR_FIELD(paramtype);
 
 	return newnode;
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index 9aa0b399b7c..94799d0c85f 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -18,7 +18,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/equalfuncs.c,v 1.269 2006/04/15 17:45:34 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/equalfuncs.c,v 1.270 2006/04/22 01:25:59 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -147,23 +147,9 @@ static bool
 _equalParam(Param *a, Param *b)
 {
 	COMPARE_SCALAR_FIELD(paramkind);
+	COMPARE_SCALAR_FIELD(paramid);
 	COMPARE_SCALAR_FIELD(paramtype);
 
-	switch (a->paramkind)
-	{
-		case PARAM_NAMED:
-			COMPARE_STRING_FIELD(paramname);
-			break;
-		case PARAM_NUM:
-		case PARAM_EXEC:
-		case PARAM_SUBLINK:
-			COMPARE_SCALAR_FIELD(paramid);
-			break;
-		default:
-			elog(ERROR, "unrecognized paramkind: %d",
-				 a->paramkind);
-	}
-
 	return true;
 }
 
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index 58e800bab2b..314d68d2ef9 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.272 2006/03/23 00:19:29 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.273 2006/04/22 01:25:59 tgl Exp $
  *
  * NOTES
  *	  Every node type that can appear in stored rules' parsetrees *must*
@@ -624,9 +624,8 @@ _outParam(StringInfo str, Param *node)
 {
 	WRITE_NODE_TYPE("PARAM");
 
-	WRITE_INT_FIELD(paramkind);
+	WRITE_ENUM_FIELD(paramkind, ParamKind);
 	WRITE_INT_FIELD(paramid);
-	WRITE_STRING_FIELD(paramname);
 	WRITE_OID_FIELD(paramtype);
 }
 
diff --git a/src/backend/nodes/params.c b/src/backend/nodes/params.c
index 618a1c1e816..1d4e1d48e8b 100644
--- a/src/backend/nodes/params.c
+++ b/src/backend/nodes/params.c
@@ -1,13 +1,14 @@
 /*-------------------------------------------------------------------------
  *
  * params.c
- *	  Support functions for plan parameter lists.
+ *	  Support for finding the values associated with Param nodes.
+ *
  *
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/params.c,v 1.5 2006/03/05 15:58:28 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/params.c,v 1.6 2006/04/22 01:25:59 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -20,7 +21,7 @@
 
 
 /*
- * Copy a ParamList.
+ * Copy a ParamListInfo structure.
  *
  * The result is allocated in CurrentMemoryContext.
  */
@@ -28,97 +29,34 @@ ParamListInfo
 copyParamList(ParamListInfo from)
 {
 	ParamListInfo retval;
-	int			i,
-				size;
+	Size		size;
+	int			i;
 
-	if (from == NULL)
+	if (from == NULL || from->numParams <= 0)
 		return NULL;
 
-	size = 0;
-	while (from[size].kind != PARAM_INVALID)
-		size++;
+	/* sizeof(ParamListInfoData) includes the first array element */
+	size = sizeof(ParamListInfoData) +
+		(from->numParams - 1) * sizeof(ParamExternData);
 
-	retval = (ParamListInfo) palloc0((size + 1) * sizeof(ParamListInfoData));
+	retval = (ParamListInfo) palloc(size);
+	memcpy(retval, from, size);
 
-	for (i = 0; i < size; i++)
+	/*
+	 * Flat-copy is not good enough for pass-by-ref data values, so make
+	 * a pass over the array to copy those.
+	 */
+	for (i = 0; i < retval->numParams; i++)
 	{
-		/* copy metadata */
-		retval[i].kind = from[i].kind;
-		if (from[i].kind == PARAM_NAMED)
-			retval[i].name = pstrdup(from[i].name);
-		retval[i].id = from[i].id;
-		retval[i].ptype = from[i].ptype;
-
-		/* copy value */
-		retval[i].isnull = from[i].isnull;
-		if (from[i].isnull)
-		{
-			retval[i].value = from[i].value;	/* nulls just copy */
-		}
-		else
-		{
-			int16		typLen;
-			bool		typByVal;
-
-			get_typlenbyval(from[i].ptype, &typLen, &typByVal);
-			retval[i].value = datumCopy(from[i].value, typByVal, typLen);
-		}
+		ParamExternData *prm = &retval->params[i];
+		int16		typLen;
+		bool		typByVal;
+
+		if (prm->isnull || !OidIsValid(prm->ptype))
+			continue;
+		get_typlenbyval(prm->ptype, &typLen, &typByVal);
+		prm->value = datumCopy(prm->value, typByVal, typLen);
 	}
 
-	retval[size].kind = PARAM_INVALID;
-
 	return retval;
 }
-
-/*
- * Search a ParamList for a given parameter.
- *
- * On success, returns a pointer to the parameter's entry.
- * On failure, returns NULL if noError is true, else ereports the error.
- */
-ParamListInfo
-lookupParam(ParamListInfo paramList, int thisParamKind,
-			const char *thisParamName, AttrNumber thisParamId,
-			bool noError)
-{
-	if (paramList != NULL)
-	{
-		while (paramList->kind != PARAM_INVALID)
-		{
-			if (thisParamKind == paramList->kind)
-			{
-				switch (thisParamKind)
-				{
-					case PARAM_NAMED:
-						if (strcmp(paramList->name, thisParamName) == 0)
-							return paramList;
-						break;
-					case PARAM_NUM:
-						if (paramList->id == thisParamId)
-							return paramList;
-						break;
-					default:
-						elog(ERROR, "unrecognized paramkind: %d",
-							 thisParamKind);
-				}
-			}
-			paramList++;
-		}
-	}
-
-	if (!noError)
-	{
-		if (thisParamKind == PARAM_NAMED)
-			ereport(ERROR,
-					(errcode(ERRCODE_UNDEFINED_OBJECT),
-					 errmsg("no value found for parameter \"%s\"",
-							thisParamName)));
-		else
-			ereport(ERROR,
-					(errcode(ERRCODE_UNDEFINED_OBJECT),
-					 errmsg("no value found for parameter %d",
-							thisParamId)));
-	}
-
-	return NULL;
-}
diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c
index 4e762d3a2ec..9fdf02fd568 100644
--- a/src/backend/nodes/readfuncs.c
+++ b/src/backend/nodes/readfuncs.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/readfuncs.c,v 1.187 2006/03/16 00:31:55 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/readfuncs.c,v 1.188 2006/04/22 01:25:59 tgl Exp $
  *
  * NOTES
  *	  Path and Plan nodes do not have any readfuncs support, because we
@@ -318,9 +318,8 @@ _readParam(void)
 {
 	READ_LOCALS(Param);
 
-	READ_INT_FIELD(paramkind);
+	READ_ENUM_FIELD(paramkind, ParamKind);
 	READ_INT_FIELD(paramid);
-	READ_STRING_FIELD(paramname);
 	READ_OID_FIELD(paramtype);
 
 	READ_DONE();
diff --git a/src/backend/optimizer/plan/subselect.c b/src/backend/optimizer/plan/subselect.c
index 1b64bf1c931..5296bb04359 100644
--- a/src/backend/optimizer/plan/subselect.c
+++ b/src/backend/optimizer/plan/subselect.c
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/plan/subselect.c,v 1.104 2006/03/05 15:58:30 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/plan/subselect.c,v 1.105 2006/04/22 01:25:59 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -163,7 +163,7 @@ replace_outer_var(Var *var)
 
 	retval = makeNode(Param);
 	retval->paramkind = PARAM_EXEC;
-	retval->paramid = (AttrNumber) i;
+	retval->paramid = i;
 	retval->paramtype = var->vartype;
 
 	return retval;
@@ -201,7 +201,7 @@ replace_outer_agg(Aggref *agg)
 
 	retval = makeNode(Param);
 	retval->paramkind = PARAM_EXEC;
-	retval->paramid = (AttrNumber) i;
+	retval->paramid = i;
 	retval->paramtype = agg->aggtype;
 
 	return retval;
@@ -222,7 +222,7 @@ generate_new_param(Oid paramtype, int32 paramtypmod)
 
 	retval = makeNode(Param);
 	retval->paramkind = PARAM_EXEC;
-	retval->paramid = (AttrNumber) list_length(PlannerParamList);
+	retval->paramid = list_length(PlannerParamList);
 	retval->paramtype = paramtype;
 
 	pitem = (PlannerParamItem *) palloc(sizeof(PlannerParamItem));
@@ -1211,7 +1211,7 @@ finalize_primnode(Node *node, finalize_primnode_context *context)
 	{
 		if (((Param *) node)->paramkind == PARAM_EXEC)
 		{
-			int			paramid = (int) ((Param *) node)->paramid;
+			int			paramid = ((Param *) node)->paramid;
 
 			context->paramids = bms_add_member(context->paramids, paramid);
 		}
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index aa21dfdac95..10a994bcb3f 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.210 2006/03/14 22:48:19 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.211 2006/04/22 01:25:59 tgl Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -1500,36 +1500,35 @@ eval_const_expressions_mutator(Node *node,
 		Param	   *param = (Param *) node;
 
 		/* OK to try to substitute value? */
-		if (context->estimate && param->paramkind != PARAM_EXEC &&
+		if (context->estimate && param->paramkind == PARAM_EXTERN &&
 			PlannerBoundParamList != NULL)
 		{
-			ParamListInfo paramInfo;
-
-			/* Search to see if we've been given a value for this Param */
-			paramInfo = lookupParam(PlannerBoundParamList,
-									param->paramkind,
-									param->paramname,
-									param->paramid,
-									true);
-			if (paramInfo)
+			/* Look to see if we've been given a value for this Param */
+			if (param->paramid > 0 &&
+				param->paramid <= PlannerBoundParamList->numParams)
 			{
-				/*
-				 * Found it, so return a Const representing the param value.
-				 * Note that we don't copy pass-by-ref datatypes, so the Const
-				 * will only be valid as long as the bound parameter list
-				 * exists. This is okay for intended uses of
-				 * estimate_expression_value().
-				 */
-				int16		typLen;
-				bool		typByVal;
-
-				Assert(paramInfo->ptype == param->paramtype);
-				get_typlenbyval(param->paramtype, &typLen, &typByVal);
-				return (Node *) makeConst(param->paramtype,
-										  (int) typLen,
-										  paramInfo->value,
-										  paramInfo->isnull,
-										  typByVal);
+				ParamExternData *prm = &PlannerBoundParamList->params[param->paramid - 1];
+
+				if (OidIsValid(prm->ptype))
+				{
+					/*
+					 * Found it, so return a Const representing the param
+					 * value.  Note that we don't copy pass-by-ref datatypes,
+					 * so the Const will only be valid as long as the bound
+					 * parameter list exists.  This is okay for intended uses
+					 * of estimate_expression_value().
+					 */
+					int16		typLen;
+					bool		typByVal;
+
+					Assert(prm->ptype == param->paramtype);
+					get_typlenbyval(param->paramtype, &typLen, &typByVal);
+					return (Node *) makeConst(param->paramtype,
+											  (int) typLen,
+											  prm->value,
+											  prm->isnull,
+											  typByVal);
+				}
 			}
 		}
 		/* Not replaceable, so just copy the Param (no need to recurse) */
@@ -2810,8 +2809,8 @@ substitute_actual_parameters_mutator(Node *node,
 	{
 		Param	   *param = (Param *) node;
 
-		if (param->paramkind != PARAM_NUM)
-			elog(ERROR, "unexpected paramkind: %d", param->paramkind);
+		if (param->paramkind != PARAM_EXTERN)
+			elog(ERROR, "unexpected paramkind: %d", (int) param->paramkind);
 		if (param->paramid <= 0 || param->paramid > context->nargs)
 			elog(ERROR, "invalid paramid: %d", param->paramid);
 
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 39c562b8188..d69c0f17864 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- *	$PostgreSQL: pgsql/src/backend/parser/analyze.c,v 1.332 2006/03/23 00:19:29 tgl Exp $
+ *	$PostgreSQL: pgsql/src/backend/parser/analyze.c,v 1.333 2006/04/22 01:25:59 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -3205,7 +3205,7 @@ check_parameter_resolution_walker(Node *node,
 	{
 		Param	   *param = (Param *) node;
 
-		if (param->paramkind == PARAM_NUM)
+		if (param->paramkind == PARAM_EXTERN)
 		{
 			int			paramno = param->paramid;
 
diff --git a/src/backend/parser/parse_coerce.c b/src/backend/parser/parse_coerce.c
index 98393a54aa1..3f5d8563f60 100644
--- a/src/backend/parser/parse_coerce.c
+++ b/src/backend/parser/parse_coerce.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/parse_coerce.c,v 2.137 2006/04/05 22:11:55 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/parse_coerce.c,v 2.138 2006/04/22 01:25:59 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -210,7 +210,7 @@ coerce_type(ParseState *pstate, Node *node,
 		return result;
 	}
 	if (inputTypeId == UNKNOWNOID && IsA(node, Param) &&
-		((Param *) node)->paramkind == PARAM_NUM &&
+		((Param *) node)->paramkind == PARAM_EXTERN &&
 		pstate != NULL && pstate->p_variableparams)
 	{
 		/*
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index cae682c9e77..414afe6dfa5 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/parse_expr.c,v 1.191 2006/03/14 22:48:21 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/parse_expr.c,v 1.192 2006/04/22 01:26:00 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -568,8 +568,8 @@ transformParamRef(ParseState *pstate, ParamRef *pref)
 	}
 
 	param = makeNode(Param);
-	param->paramkind = PARAM_NUM;
-	param->paramid = (AttrNumber) paramno;
+	param->paramkind = PARAM_EXTERN;
+	param->paramid = paramno;
 	param->paramtype = toppstate->p_paramtypes[paramno - 1];
 
 	return (Node *) param;
@@ -1177,7 +1177,7 @@ transformSubLink(ParseState *pstate, SubLink *sublink)
 
 			param = makeNode(Param);
 			param->paramkind = PARAM_SUBLINK;
-			param->paramid = (AttrNumber) tent->resno;
+			param->paramid = tent->resno;
 			param->paramtype = exprType((Node *) tent->expr);
 
 			right_list = lappend(right_list, param);
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 3c24fa532a6..04e432594e3 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/tcop/postgres.c,v 1.484 2006/04/18 00:52:23 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/tcop/postgres.c,v 1.485 2006/04/22 01:26:00 tgl Exp $
  *
  * NOTES
  *	  this is the "main" module of the postgres backend and
@@ -1479,8 +1479,10 @@ exec_bind_message(StringInfo input_message)
 
 		oldContext = MemoryContextSwitchTo(PortalGetHeapMemory(portal));
 
-		params = (ParamListInfo)
-			palloc0((numParams + 1) * sizeof(ParamListInfoData));
+		/* sizeof(ParamListInfoData) includes the first array element */
+		params = (ParamListInfo) palloc(sizeof(ParamListInfoData) +
+								(numParams - 1) * sizeof(ParamExternData));
+		params->numParams = numParams;
 
 		i = 0;
 		foreach(l, pstmt->argtype_list)
@@ -1545,8 +1547,10 @@ exec_bind_message(StringInfo input_message)
 				else
 					pstring = pg_client_to_server(pbuf.data, plength);
 
-				params[i].value = OidInputFunctionCall(typinput, pstring,
-													   typioparam, -1);
+				params->params[i].value = OidInputFunctionCall(typinput,
+															   pstring,
+															   typioparam,
+															   -1);
 				/* Free result of encoding conversion, if any */
 				if (pstring && pstring != pbuf.data)
 					pfree(pstring);
@@ -1567,8 +1571,10 @@ exec_bind_message(StringInfo input_message)
 				else
 					bufptr = &pbuf;
 
-				params[i].value = OidReceiveFunctionCall(typreceive, bufptr,
-														 typioparam, -1);
+				params->params[i].value = OidReceiveFunctionCall(typreceive,
+																 bufptr,
+																 typioparam,
+																 -1);
 
 				/* Trouble if it didn't eat the whole buffer */
 				if (!isNull && pbuf.cursor != pbuf.len)
@@ -1589,16 +1595,12 @@ exec_bind_message(StringInfo input_message)
 			if (!isNull)
 				pbuf.data[plength] = csave;
 
-			params[i].kind = PARAM_NUM;
-			params[i].id = i + 1;
-			params[i].ptype = ptype;
-			params[i].isnull = isNull;
+			params->params[i].isnull = isNull;
+			params->params[i].ptype = ptype;
 
 			i++;
 		}
 
-		params[i].kind = PARAM_INVALID;
-
 		MemoryContextSwitchTo(oldContext);
 	}
 	else
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 902af40d9fc..c0db64bf896 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -2,7 +2,7 @@
  * ruleutils.c	- Functions to convert stored expressions/querytrees
  *				back to source text
  *
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/ruleutils.c,v 1.219 2006/04/08 18:49:52 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/ruleutils.c,v 1.220 2006/04/22 01:26:00 tgl Exp $
  **********************************************************************/
 
 #include "postgres.h"
@@ -3120,24 +3120,7 @@ get_rule_expr(Node *node, deparse_context *context,
 			break;
 
 		case T_Param:
-			{
-				Param	   *param = (Param *) node;
-
-				switch (param->paramkind)
-				{
-					case PARAM_NAMED:
-						appendStringInfo(buf, "$%s", param->paramname);
-						break;
-					case PARAM_NUM:
-					case PARAM_EXEC:
-					case PARAM_SUBLINK:
-						appendStringInfo(buf, "$%d", param->paramid);
-						break;
-					default:
-						appendStringInfo(buf, "(param)");
-						break;
-				}
-			}
+			appendStringInfo(buf, "$%d", ((Param *) node)->paramid);
 			break;
 
 		case T_Aggref:
diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index 6b59dd55fe1..a88d3cfd597 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -37,7 +37,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.322 2006/04/05 22:11:55 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/catversion.h,v 1.323 2006/04/22 01:26:01 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	200604051
+#define CATALOG_VERSION_NO	200604211
 
 #endif
diff --git a/src/include/nodes/params.h b/src/include/nodes/params.h
index a00ded8e0a6..13eb25876dd 100644
--- a/src/include/nodes/params.h
+++ b/src/include/nodes/params.h
@@ -1,87 +1,47 @@
 /*-------------------------------------------------------------------------
  *
  * params.h
- *	  Declarations of stuff needed to handle parameterized plans.
+ *	  Support for finding the values associated with Param nodes.
  *
  *
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/params.h,v 1.30 2006/03/05 15:58:56 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/params.h,v 1.31 2006/04/22 01:26:01 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
 #ifndef PARAMS_H
 #define PARAMS_H
 
-#include "access/attnum.h"
-
-
-/* ----------------
- * The following are the possible values for the 'paramkind'
- * field of a Param node.
- *
- * PARAM_NAMED: The parameter has a name, i.e. something
- *				like `$.salary' or `$.foobar'.
- *				In this case field `paramname' must be a valid name.
- *
- * PARAM_NUM:	The parameter has only a numeric identifier,
- *				i.e. something like `$1', `$2' etc.
- *				The number is contained in the `paramid' field.
- *
- * PARAM_EXEC:	The parameter is an internal executor parameter.
- *				It has a number contained in the `paramid' field.
- *
- * PARAM_SUBLINK: The parameter represents an output column of a SubLink
- *				node's sub-select.  The column number is contained in the
- *				`paramid' field.  (This type of Param is converted to
- *				PARAM_EXEC during planning.)
- *
- * PARAM_INVALID should never appear in a Param node; it's used to mark
- * the end of a ParamListInfo array.
- *
- * NOTE: As of PostgreSQL 7.3, named parameters aren't actually used and
- * so the code that handles PARAM_NAMED cases is dead code.  We leave it
- * in place since it might be resurrected someday.
- * ----------------
- */
-
-#define PARAM_NAMED		11
-#define PARAM_NUM		12
-#define PARAM_EXEC		15
-#define PARAM_SUBLINK	16
-#define PARAM_INVALID	100
-
 
 /* ----------------
  *	  ParamListInfo
  *
- *	  ParamListInfo entries are used to pass parameters into the executor
+ *	  ParamListInfo arrays are used to pass parameters into the executor
  *	  for parameterized plans.	Each entry in the array defines the value
- *	  to be substituted for a PARAM_NAMED or PARAM_NUM parameter.
+ *	  to be substituted for a PARAM_EXTERN parameter.  The "paramid"
+ *	  of a PARAM_EXTERN Param can range from 1 to numParams.
  *
- *		kind   : the kind of parameter (PARAM_NAMED or PARAM_NUM)
- *		name   : the parameter name (valid if kind == PARAM_NAMED)
- *		id	   : the parameter id (valid if kind == PARAM_NUM)
- *		ptype  : the type of the parameter value
- *		isnull : true if the value is null (if so 'value' is undefined)
- *		value  : the value that has to be substituted in the place
- *				 of the parameter.
+ *	  Although parameter numbers are normally consecutive, we allow
+ *	  ptype == InvalidOid to signal an unused array entry.
  *
- *	 ParamListInfo is to be used as an array of ParamListInfoData
- *	 records.  A dummy record with kind == PARAM_INVALID marks the end
- *	 of the array.
+ *	  Although the data structure is really an array, not a list, we keep
+ *	  the old typedef name to avoid unnecessary code changes.
  * ----------------
  */
 
+typedef struct ParamExternData
+{
+	Datum		value;			/* parameter value */
+	bool		isnull;			/* is it NULL? */
+	Oid			ptype;			/* parameter's datatype, or 0 */
+} ParamExternData;
+
 typedef struct ParamListInfoData
 {
-	int			kind;
-	char	   *name;
-	AttrNumber	id;
-	Oid			ptype;
-	bool		isnull;
-	Datum		value;
+	int			numParams;		/* number of ParamExternDatas following */
+	ParamExternData params[1];	/* VARIABLE LENGTH ARRAY */
 } ParamListInfoData;
 
 typedef ParamListInfoData *ParamListInfo;
@@ -114,8 +74,5 @@ typedef struct ParamExecData
 
 /* Functions found in src/backend/nodes/params.c */
 extern ParamListInfo copyParamList(ParamListInfo from);
-extern ParamListInfo lookupParam(ParamListInfo paramList, int thisParamKind,
-			const char *thisParamName, AttrNumber thisParamId,
-			bool noError);
 
 #endif   /* PARAMS_H */
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index 65d5d8ff0c7..9c1f580fc98 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -10,7 +10,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/primnodes.h,v 1.112 2006/03/05 15:58:57 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/primnodes.h,v 1.113 2006/04/22 01:26:01 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -146,18 +146,15 @@ typedef struct Const
 /* ----------------
  * Param
  *		paramkind - specifies the kind of parameter. The possible values
- *		for this field are specified in "params.h", and they are:
+ *		for this field are:
  *
- *		PARAM_NAMED: The parameter has a name, i.e. something
- *				like `$.salary' or `$.foobar'.
- *				In this case field `paramname' must be a valid name.
+ *		PARAM_EXTERN:  The parameter value is supplied from outside the plan.
+ *				Such parameters are numbered from 1 to n.
  *
- *		PARAM_NUM:	 The parameter has only a numeric identifier,
- *				i.e. something like `$1', `$2' etc.
- *				The number is contained in the `paramid' field.
- *
- *		PARAM_EXEC:  The parameter is an internal executor parameter.
- *				It has a number contained in the `paramid' field.
+ *		PARAM_EXEC:  The parameter is an internal executor parameter, used
+ *				for passing values into and out of sub-queries.
+ *				For historical reasons, such parameters are numbered from 0.
+ *				These numbers are independent of PARAM_EXTERN numbers.
  *
  *		PARAM_SUBLINK:  The parameter represents an output column of a SubLink
  *				node's sub-select.  The column number is contained in the
@@ -165,12 +162,18 @@ typedef struct Const
  *				PARAM_EXEC during planning.)
  * ----------------
  */
+typedef enum ParamKind
+{
+	PARAM_EXTERN,
+	PARAM_EXEC,
+	PARAM_SUBLINK
+} ParamKind;
+
 typedef struct Param
 {
 	Expr		xpr;
-	int			paramkind;		/* kind of parameter. See above */
-	AttrNumber	paramid;		/* numeric ID for parameter ("$1") */
-	char	   *paramname;		/* name for parameter ("$.foo") */
+	ParamKind	paramkind;		/* kind of parameter. See above */
+	int			paramid;		/* numeric ID for parameter */
 	Oid			paramtype;		/* PG_TYPE OID of parameter's datatype */
 } Param;
 
diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index 8a82a42fbe6..ee30902dedb 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.163 2006/04/04 19:35:37 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.164 2006/04/22 01:26:01 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -3786,24 +3786,27 @@ exec_eval_simple_expr(PLpgSQL_execstate *estate,
 	 * back for subscript evaluation, and so there can be a need to have more
 	 * than one active param list.
 	 */
-	paramLI = (ParamListInfo)
-		MemoryContextAlloc(econtext->ecxt_per_tuple_memory,
-						   (expr->nparams + 1) * sizeof(ParamListInfoData));
-
-	/*
-	 * Put the parameter values into the parameter list entries.
-	 */
-	for (i = 0; i < expr->nparams; i++)
+	if (expr->nparams > 0)
 	{
-		PLpgSQL_datum *datum = estate->datums[expr->params[i]];
+		/* sizeof(ParamListInfoData) includes the first array element */
+		paramLI = (ParamListInfo)
+			MemoryContextAlloc(econtext->ecxt_per_tuple_memory,
+							   sizeof(ParamListInfoData) +
+							   (expr->nparams - 1) * sizeof(ParamExternData));
+		paramLI->numParams = expr->nparams;
+
+		for (i = 0; i < expr->nparams; i++)
+		{
+			ParamExternData *prm = &paramLI->params[i];
+			PLpgSQL_datum *datum = estate->datums[expr->params[i]];
 
-		paramLI[i].kind = PARAM_NUM;
-		paramLI[i].id = i + 1;
-		exec_eval_datum(estate, datum, expr->plan_argtypes[i],
-						&paramLI[i].ptype,
-						&paramLI[i].value, &paramLI[i].isnull);
+			exec_eval_datum(estate, datum, expr->plan_argtypes[i],
+							&prm->ptype,
+							&prm->value, &prm->isnull);
+		}
 	}
-	paramLI[i].kind = PARAM_INVALID;
+	else
+		paramLI = NULL;
 
 	/*
 	 * Now we can safely make the econtext point to the param list.