Modify processing of DECLARE CURSOR and EXPLAIN so that they can resolve the

types of unspecified parameters when submitted via extended query protocol.
This worked in 8.2 but I had broken it during plancache changes.  DECLARE
CURSOR is now treated almost exactly like a plain SELECT through parse
analysis, rewrite, and planning; only just before sending to the executor
do we divert it away to ProcessUtility.  This requires a special-case check
in a number of places, but practically all of them were already special-casing
SELECT INTO, so it's not too ugly.  (Maybe it would be a good idea to merge
the two by treating IntoClause as a form of utility statement?  Not going to
worry about that now, though.)  That approach doesn't work for EXPLAIN,
however, so for that I punted and used a klugy solution of running parse
analysis an extra time if under extended query protocol.

3 files changed, 23 insertions, 15 deletions

diff --git a/src/backend/executor/execMain.c b/src/backend/executor/execMain.c
index cacd7c6fe70..298d0c69c9d 100644
--- a/src/backend/executor/execMain.c
+++ b/src/backend/executor/execMain.c
@@ -26,7 +26,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/executor/execMain.c,v 1.292 2007/03/29 00:15:38 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/execMain.c,v 1.293 2007/04/27 22:05:47 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -420,7 +420,7 @@ ExecCheckXactReadOnly(PlannedStmt *plannedstmt)
 	 *
 	 * XXX should we allow this if the destination is temp?
 	 */
-	if (plannedstmt->into != NULL)
+	if (plannedstmt->intoClause != NULL)
 		goto fail;
 
 	/* Fail if write permissions are requested on any non-temp table */
@@ -522,10 +522,10 @@ InitPlan(QueryDesc *queryDesc, int eflags)
 	 * correct tuple descriptors.  (Other SELECT INTO stuff comes later.)
 	 */
 	estate->es_select_into = false;
-	if (operation == CMD_SELECT && plannedstmt->into != NULL)
+	if (operation == CMD_SELECT && plannedstmt->intoClause != NULL)
 	{
 		estate->es_select_into = true;
-		estate->es_into_oids = interpretOidsOption(plannedstmt->into->options);
+		estate->es_into_oids = interpretOidsOption(plannedstmt->intoClause->options);
 	}
 
 	/*
@@ -2395,7 +2395,7 @@ typedef struct
 static void
 OpenIntoRel(QueryDesc *queryDesc)
 {
-	IntoClause *into = queryDesc->plannedstmt->into;
+	IntoClause *into = queryDesc->plannedstmt->intoClause;
 	EState	   *estate = queryDesc->estate;
 	Relation	intoRelationDesc;
 	char	   *intoName;
diff --git a/src/backend/executor/functions.c b/src/backend/executor/functions.c
index b59228b0c9e..9ad13916123 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 1.115 2007/04/16 01:14:56 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/functions.c,v 1.116 2007/04/27 22:05:47 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -317,7 +317,7 @@ postquel_start(execution_state *es, SQLFunctionCachePtr fcache)
 	/* We assume we don't need to set up ActiveSnapshot for ExecutorStart */
 
 	/* Utility commands don't need Executor. */
-	if (es->qd->operation != CMD_UTILITY)
+	if (es->qd->utilitystmt == NULL)
 	{
 		/*
 		 * Only set up to collect queued triggers if it's not a SELECT.
@@ -346,9 +346,12 @@ postquel_getnext(execution_state *es, SQLFunctionCachePtr fcache)
 	{
 		ActiveSnapshot = es->qd->snapshot;
 
-		if (es->qd->operation == CMD_UTILITY)
+		if (es->qd->utilitystmt)
 		{
-			ProcessUtility(es->qd->utilitystmt,
+			/* ProcessUtility needs the PlannedStmt for DECLARE CURSOR */
+			ProcessUtility((es->qd->plannedstmt ?
+							(Node *) es->qd->plannedstmt :
+							es->qd->utilitystmt),
 						   fcache->src,
 						   es->qd->params,
 						   false,				/* not top level */
@@ -366,7 +369,8 @@ postquel_getnext(execution_state *es, SQLFunctionCachePtr fcache)
 			 */
 			if (LAST_POSTQUEL_COMMAND(es) &&
 				es->qd->operation == CMD_SELECT &&
-				es->qd->plannedstmt->into == NULL)
+				es->qd->plannedstmt->utilityStmt == NULL &&
+				es->qd->plannedstmt->intoClause == NULL)
 				count = 1L;
 			else
 				count = 0L;
@@ -396,7 +400,7 @@ postquel_end(execution_state *es)
 	es->status = F_EXEC_DONE;
 
 	/* Utility commands don't need Executor. */
-	if (es->qd->operation != CMD_UTILITY)
+	if (es->qd->utilitystmt == NULL)
 	{
 		/* Make our snapshot the active one for any called functions */
 		saveActiveSnapshot = ActiveSnapshot;
@@ -894,7 +898,9 @@ check_sql_fn_retval(Oid func_id, Oid rettype, List *queryTreeList,
 	 * Note: eventually replace this test with QueryReturnsTuples?  We'd need
 	 * a more general method of determining the output type, though.
 	 */
-	if (!(parse->commandType == CMD_SELECT && parse->into == NULL))
+	if (!(parse->commandType == CMD_SELECT &&
+		  parse->utilityStmt == NULL &&
+		  parse->intoClause == NULL))
 	{
 		if (rettype != VOIDOID)
 			ereport(ERROR,
diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index 0a5625a0c58..f97a86fe214 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 1.178 2007/04/16 18:21:07 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/executor/spi.c,v 1.179 2007/04/27 22:05:47 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1581,7 +1581,8 @@ _SPI_execute_plan(SPIPlanPtr plan, Datum *Values, const char *Nulls,
 						ActiveSnapshot->curcid = GetCurrentCommandId();
 				}
 
-				if (IsA(stmt, PlannedStmt))
+				if (IsA(stmt, PlannedStmt) &&
+					((PlannedStmt *) stmt)->utilityStmt == NULL)
 				{
 					qdesc = CreateQueryDesc((PlannedStmt *) stmt,
 											ActiveSnapshot,
@@ -1687,7 +1688,8 @@ _SPI_pquery(QueryDesc *queryDesc, long tcount)
 	switch (operation)
 	{
 		case CMD_SELECT:
-			if (queryDesc->plannedstmt->into)		/* select into table? */
+			Assert(queryDesc->plannedstmt->utilityStmt == NULL);
+			if (queryDesc->plannedstmt->intoClause)	/* select into table? */
 				res = SPI_OK_SELINTO;
 			else if (queryDesc->dest->mydest != DestSPI)
 			{