Remove the Query structure from the executor's API. This allows us to stop

storing mostly-redundant Query trees in prepared statements, portals, etc.
To replace Query, a new node type called PlannedStmt is inserted by the
planner at the top of a completed plan tree; this carries just the fields of
Query that are still needed at runtime.  The statement lists kept in portals
etc. now consist of intermixed PlannedStmt and bare utility-statement nodes
--- no Query.  This incidentally allows us to remove some fields from Query
and Plan nodes that shouldn't have been there in the first place.

Still to do: simplify the execution-time range table; at the moment the
range table passed to the executor still contains Query trees for subqueries.

initdb forced due to change of stored rules.

Author: tglsfdc

src/backend/commands/copy.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/copy.c,v 1.275 2007/01/25 02:17:26 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/copy.c,v 1.276 2007/02/20 17:32:13 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -986,10 +986,11 @@ DoCopy(const CopyStmt *stmt)
 	{
 		Query	   *query = stmt->query;
 		List	   *rewritten;
-		Plan	   *plan;
+		PlannedStmt *plan;
 		DestReceiver *dest;
 
 		Assert(query);
+		Assert(query->commandType == CMD_SELECT);
 		Assert(!is_from);
 		cstate->rel = NULL;
 
@@ -999,6 +1000,7 @@ DoCopy(const CopyStmt *stmt)
 					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 					 errmsg("COPY (SELECT) WITH OIDS is not supported")));
 
+		/* Query mustn't use INTO, either */
 		if (query->into)
 			ereport(ERROR,
 					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -1016,7 +1018,6 @@ DoCopy(const CopyStmt *stmt)
 		 * shouldn't modify its input ... FIXME someday.
 		 */
 		query = copyObject(query);
-		Assert(query->commandType == CMD_SELECT);
 
 		/*
 		 * Must acquire locks in case we didn't come fresh from the parser.
@@ -1051,7 +1052,7 @@ DoCopy(const CopyStmt *stmt)
 		((DR_copy *) dest)->cstate = cstate;
 
 		/* Create a QueryDesc requesting no output */
-		cstate->queryDesc = CreateQueryDesc(query, plan,
+		cstate->queryDesc = CreateQueryDesc(plan,
 											ActiveSnapshot, InvalidSnapshot,
 											dest, NULL, false);
 

src/backend/commands/explain.c

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994-5, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/explain.c,v 1.155 2007/02/19 02:23:11 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/explain.c,v 1.156 2007/02/20 17:32:14 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -149,7 +149,7 @@ static void
 ExplainOneQuery(Query *query, ExplainStmt *stmt, ParamListInfo params,
 				TupOutputState *tstate)
 {
-	Plan	   *plan;
+	PlannedStmt *plan;
 	QueryDesc  *queryDesc;
 	bool		isCursor = false;
 	int			cursorOptions = 0;
@@ -203,7 +203,7 @@ ExplainOneQuery(Query *query, ExplainStmt *stmt, ParamListInfo params,
 	ActiveSnapshot->curcid = GetCurrentCommandId();
 
 	/* Create a QueryDesc requesting no output */
-	queryDesc = CreateQueryDesc(query, plan,
+	queryDesc = CreateQueryDesc(plan,
 								ActiveSnapshot, InvalidSnapshot,
 								None_Receiver, params,
 								stmt->analyze);
@@ -260,14 +260,14 @@ ExplainOnePlan(QueryDesc *queryDesc, ExplainStmt *stmt,
 
 	es->printNodes = stmt->verbose;
 	es->printAnalyze = stmt->analyze;
-	es->rtable = queryDesc->parsetree->rtable;
+	es->rtable = queryDesc->plannedstmt->rtable;
 
 	if (es->printNodes)
 	{
 		char	   *s;
 		char	   *f;
 
-		s = nodeToString(queryDesc->plantree);
+		s = nodeToString(queryDesc->plannedstmt->planTree);
 		if (s)
 		{
 			if (Explain_pretty_print)
@@ -282,7 +282,8 @@ ExplainOnePlan(QueryDesc *queryDesc, ExplainStmt *stmt,
 	}
 
 	initStringInfo(&buf);
-	explain_outNode(&buf, queryDesc->plantree, queryDesc->planstate,
+	explain_outNode(&buf,
+					queryDesc->plannedstmt->planTree, queryDesc->planstate,
 					NULL, 0, es);
 
 	/*

src/backend/commands/portalcmds.c

@@ -14,7 +14,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/portalcmds.c,v 1.60 2007/02/06 22:49:24 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/portalcmds.c,v 1.61 2007/02/20 17:32:14 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -42,7 +42,7 @@ PerformCursorOpen(DeclareCursorStmt *stmt, ParamListInfo params)
 {
 	List	   *rewritten;
 	Query	   *query;
-	Plan	   *plan;
+	PlannedStmt *plan;
 	Portal		portal;
 	MemoryContext oldContext;
 
@@ -98,13 +98,12 @@ PerformCursorOpen(DeclareCursorStmt *stmt, ParamListInfo params)
 	plan = planner(query, true, stmt->options, params);
 
 	/*
-	 * Create a portal and copy the query and plan into its memory context.
+	 * Create a portal and copy the plan into its memory context.
 	 */
 	portal = CreatePortal(stmt->portalname, false, false);
 
 	oldContext = MemoryContextSwitchTo(PortalGetHeapMemory(portal));
 
-	query = copyObject(query);
 	plan = copyObject(plan);
 
 	/*
@@ -115,7 +114,6 @@ PerformCursorOpen(DeclareCursorStmt *stmt, ParamListInfo params)
 					  NULL,
 					  debug_query_string ? pstrdup(debug_query_string) : NULL,
 					  "SELECT", /* cursor's query is always a SELECT */
-					  list_make1(query),
 					  list_make1(plan),
 					  PortalGetHeapMemory(portal));
 
@@ -140,7 +138,7 @@ PerformCursorOpen(DeclareCursorStmt *stmt, ParamListInfo params)
 	portal->cursorOptions = stmt->options;
 	if (!(portal->cursorOptions & (CURSOR_OPT_SCROLL | CURSOR_OPT_NO_SCROLL)))
 	{
-		if (ExecSupportsBackwardScan(plan))
+		if (ExecSupportsBackwardScan(plan->planTree))
 			portal->cursorOptions |= CURSOR_OPT_SCROLL;
 		else
 			portal->cursorOptions |= CURSOR_OPT_NO_SCROLL;