Separate parse-analysis for utility commands out of parser/analyze.c

(which now deals only in optimizable statements), and put that code
into a new file parser/parse_utilcmd.c.  This helps clarify and enforce
the design rule that utility statements shouldn't be processed during
the regular parse analysis phase; all interpretation of their meaning
should happen after they are given to ProcessUtility to execute.
(We need this because we don't retain any locks for a utility statement
that's in a plan cache, nor have any way to detect that it's stale.)

We are also able to simplify the API for parse_analyze() and related
routines, because they will now always return exactly one Query structure.

In passing, fix bug #3403 concerning trying to add a serial column to
an existing temp table (this is largely Heikki's work, but we needed
all that restructuring to make it safe).

src/backend/commands/indexcmds.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/indexcmds.c,v 1.159 2007/06/03 17:06:16 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/indexcmds.c,v 1.160 2007/06/23 22:12:50 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -367,7 +367,7 @@ DefineIndex(RangeVar *heapRelation,
 				/*
 				 * This shouldn't happen during CREATE TABLE, but can happen
 				 * during ALTER TABLE.	Keep message in sync with
-				 * transformIndexConstraints() in parser/analyze.c.
+				 * transformIndexConstraints() in parser/parse_utilcmd.c.
 				 */
 				ereport(ERROR,
 						(errcode(ERRCODE_UNDEFINED_COLUMN),

src/backend/commands/prepare.c

@@ -10,7 +10,7 @@
  * Copyright (c) 2002-2007, PostgreSQL Global Development Group
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/prepare.c,v 1.76 2007/05/25 17:54:25 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/prepare.c,v 1.77 2007/06/23 22:12:50 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -55,7 +55,6 @@ PrepareQuery(PrepareStmt *stmt, const char *queryString)
 {
 	Oid		   *argtypes = NULL;
 	int			nargs;
-	List	   *queries;
 	Query	   *query;
 	List	   *query_list,
 			   *plan_list;
@@ -105,7 +104,7 @@ PrepareQuery(PrepareStmt *stmt, const char *queryString)
 	 * Because parse analysis scribbles on the raw querytree, we must make
 	 * a copy to ensure we have a pristine raw tree to cache.  FIXME someday.
 	 */
-	queries = parse_analyze_varparams((Node *) copyObject(stmt->query),
+	query = parse_analyze_varparams((Node *) copyObject(stmt->query),
 									queryString,
 									&argtypes, &nargs);
 
@@ -124,15 +123,8 @@ PrepareQuery(PrepareStmt *stmt, const char *queryString)
 	}
 
 	/*
-	 * Shouldn't get any extra statements, since grammar only allows
-	 * OptimizableStmt
+	 * grammar only allows OptimizableStmt, so this check should be redundant
 	 */
-	if (list_length(queries) != 1)
-		elog(ERROR, "unexpected extra stuff in prepared statement");
-
-	query = (Query *) linitial(queries);
-	Assert(IsA(query, Query));
-
 	switch (query->commandType)
 	{
 		case CMD_SELECT:

src/backend/commands/schemacmds.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/schemacmds.c,v 1.45 2007/03/23 19:53:51 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/schemacmds.c,v 1.46 2007/06/23 22:12:50 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -24,7 +24,7 @@
 #include "commands/dbcommands.h"
 #include "commands/schemacmds.h"
 #include "miscadmin.h"
-#include "parser/analyze.h"
+#include "parser/parse_utilcmd.h"
 #include "tcop/utility.h"
 #include "utils/acl.h"
 #include "utils/builtins.h"
@@ -111,31 +111,24 @@ CreateSchemaCommand(CreateSchemaStmt *stmt, const char *queryString)
 	/*
 	 * Examine the list of commands embedded in the CREATE SCHEMA command, and
 	 * reorganize them into a sequentially executable order with no forward
-	 * references.	Note that the result is still a list of raw parsetrees in
-	 * need of parse analysis --- we cannot, in general, run analyze.c on one
-	 * statement until we have actually executed the prior ones.
+	 * references.	Note that the result is still a list of raw parsetrees
+	 * --- we cannot, in general, run parse analysis on one statement until
+	 * we have actually executed the prior ones.
 	 */
-	parsetree_list = analyzeCreateSchemaStmt(stmt);
+	parsetree_list = transformCreateSchemaStmt(stmt);
 
 	/*
-	 * Analyze and execute each command contained in the CREATE SCHEMA
+	 * Execute each command contained in the CREATE SCHEMA.  Since the
+	 * grammar allows only utility commands in CREATE SCHEMA, there is
+	 * no need to pass them through parse_analyze() or the rewriter;
+	 * we can just hand them straight to ProcessUtility.
 	 */
 	foreach(parsetree_item, parsetree_list)
 	{
-		Node	   *parsetree = (Node *) lfirst(parsetree_item);
-		List	   *querytree_list;
-		ListCell   *querytree_item;
+		Node	   *stmt = (Node *) lfirst(parsetree_item);
 
-		querytree_list = parse_analyze(parsetree, queryString, NULL, 0);
-
-		foreach(querytree_item, querytree_list)
-		{
-			Query	   *querytree = (Query *) lfirst(querytree_item);
-
-			/* schemas should contain only utility stmts */
-			Assert(querytree->commandType == CMD_UTILITY);
 		/* do this step */
-			ProcessUtility(querytree->utilityStmt,
+		ProcessUtility(stmt,
 					   queryString,
 					   NULL,
 					   false,				/* not top level */
@@ -144,7 +137,6 @@ CreateSchemaCommand(CreateSchemaStmt *stmt, const char *queryString)
 		/* make sure later steps can see the object created here */
 		CommandCounterIncrement();
 	}
-	}
 
 	/* Reset search path to normal state */
 	PopOverrideSearchPath();

src/backend/commands/tablecmds.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.227 2007/06/03 22:16:03 petere Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/tablecmds.c,v 1.228 2007/06/23 22:12:50 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -44,7 +44,6 @@
 #include "optimizer/clauses.h"
 #include "optimizer/plancat.h"
 #include "optimizer/prep.h"
-#include "parser/analyze.h"
 #include "parser/gramparse.h"
 #include "parser/parse_clause.h"
 #include "parser/parse_coerce.h"
@@ -52,6 +51,7 @@
 #include "parser/parse_oper.h"
 #include "parser/parse_relation.h"
 #include "parser/parse_type.h"
+#include "parser/parse_utilcmd.h"
 #include "parser/parser.h"
 #include "rewrite/rewriteDefine.h"
 #include "rewrite/rewriteHandler.h"
@@ -394,7 +394,7 @@ DefineRelation(CreateStmt *stmt, char relkind)
 				add_nonduplicate_constraint(cdef, check, &ncheck);
 		}
 		/*
-		 * analyze.c might have passed some precooked constraints too,
+		 * parse_utilcmd.c might have passed some precooked constraints too,
 		 * due to LIKE tab INCLUDING CONSTRAINTS
 		 */
 		foreach(listptr, stmt->constraints)
@@ -2922,7 +2922,7 @@ find_composite_type_dependencies(Oid typeOid,
  *
  * Adds an additional attribute to a relation making the assumption that
  * CHECK, NOT NULL, and FOREIGN KEY constraints will be removed from the
- * AT_AddColumn AlterTableCmd by analyze.c and added as independent
+ * AT_AddColumn AlterTableCmd by parse_utilcmd.c and added as independent
  * AlterTableCmd's.
  */
 static void
@@ -3745,9 +3745,9 @@ ATExecDropColumn(Relation rel, const char *colName,
 /*
  * ALTER TABLE ADD INDEX
  *
- * There is no such command in the grammar, but the parser converts UNIQUE
- * and PRIMARY KEY constraints into AT_AddIndex subcommands.  This lets us
- * schedule creation of the index at the appropriate time during ALTER.
+ * There is no such command in the grammar, but parse_utilcmd.c converts
+ * UNIQUE and PRIMARY KEY constraints into AT_AddIndex subcommands.  This lets
+ * us schedule creation of the index at the appropriate time during ALTER.
  */
 static void
 ATExecAddIndex(AlteredTableInfo *tab, Relation rel,
@@ -3766,13 +3766,8 @@ ATExecAddIndex(AlteredTableInfo *tab, Relation rel,
 	/* suppress notices when rebuilding existing index */
 	quiet = is_rebuild;
 
-	/*
-	 * Run parse analysis.  We don't have convenient access to the query text
-	 * here, but it's probably not worth worrying about.
-	 */
-	stmt = analyzeIndexStmt(stmt, NULL);
+	/* The IndexStmt has already been through transformIndexStmt */
 
-	/* ... and do it */
 	DefineIndex(stmt->relation, /* relation */
 				stmt->idxname,	/* index name */
 				InvalidOid,		/* no predefined OID */
@@ -3806,7 +3801,7 @@ ATExecAddConstraint(AlteredTableInfo *tab, Relation rel, Node *newConstraint)
 				/*
 				 * Currently, we only expect to see CONSTR_CHECK nodes
 				 * arriving here (see the preprocessing done in
-				 * parser/analyze.c).  Use a switch anyway to make it easier
+				 * parse_utilcmd.c).  Use a switch anyway to make it easier
 				 * to add more code later.
 				 */
 				switch (constr->contype)
@@ -5239,17 +5234,27 @@ ATPostAlterTypeParse(char *cmd, List **wqueue)
 	ListCell   *list_item;
 
 	/*
-	 * We expect that we only have to do raw parsing and parse analysis, not
-	 * any rule rewriting, since these will all be utility statements.
+	 * We expect that we will get only ALTER TABLE and CREATE INDEX statements.
+	 * Hence, there is no need to pass them through parse_analyze() or the
+	 * rewriter, but instead we need to pass them through parse_utilcmd.c
+	 * to make them ready for execution.
 	 */
 	raw_parsetree_list = raw_parser(cmd);
 	querytree_list = NIL;
 	foreach(list_item, raw_parsetree_list)
 	{
-		Node	   *parsetree = (Node *) lfirst(list_item);
+		Node	   *stmt = (Node *) lfirst(list_item);
 
+		if (IsA(stmt, IndexStmt))
+			querytree_list = lappend(querytree_list,
+									 transformIndexStmt((IndexStmt *) stmt,
+														cmd));
+		else if (IsA(stmt, AlterTableStmt))
 			querytree_list = list_concat(querytree_list,
-									 parse_analyze(parsetree, cmd, NULL, 0));
+							transformAlterTableStmt((AlterTableStmt *) stmt,
+													cmd));
+		else
+			querytree_list = lappend(querytree_list, stmt);
 	}
 
 	/*
@@ -5258,17 +5263,15 @@ ATPostAlterTypeParse(char *cmd, List **wqueue)
 	 */
 	foreach(list_item, querytree_list)
 	{
-		Query	   *query = (Query *) lfirst(list_item);
+		Node	   *stm = (Node *) lfirst(list_item);
 		Relation	rel;
 		AlteredTableInfo *tab;
 
-		Assert(IsA(query, Query));
-		Assert(query->commandType == CMD_UTILITY);
-		switch (nodeTag(query->utilityStmt))
+		switch (nodeTag(stm))
 		{
 			case T_IndexStmt:
 				{
-					IndexStmt  *stmt = (IndexStmt *) query->utilityStmt;
+					IndexStmt  *stmt = (IndexStmt *) stm;
 					AlterTableCmd *newcmd;
 
 					rel = relation_openrv(stmt->relation, AccessExclusiveLock);
@@ -5283,7 +5286,7 @@ ATPostAlterTypeParse(char *cmd, List **wqueue)
 				}
 			case T_AlterTableStmt:
 				{
-					AlterTableStmt *stmt = (AlterTableStmt *) query->utilityStmt;
+					AlterTableStmt *stmt = (AlterTableStmt *) stm;
 					ListCell   *lcmd;
 
 					rel = relation_openrv(stmt->relation, AccessExclusiveLock);
@@ -5313,7 +5316,7 @@ ATPostAlterTypeParse(char *cmd, List **wqueue)
 				}
 			default:
 				elog(ERROR, "unexpected statement type: %d",
-					 (int) nodeTag(query->utilityStmt));
+					 (int) nodeTag(stm));
 		}
 	}
 }

src/backend/commands/view.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/view.c,v 1.100 2007/03/13 00:33:40 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/view.c,v 1.101 2007/06/23 22:12:50 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -351,7 +351,6 @@ UpdateRangeTableOfViewParse(Oid viewOid, Query *viewParse)
 void
 DefineView(ViewStmt *stmt, const char *queryString)
 {
-	List	   *stmts;
 	Query	   *viewParse;
 	Oid			viewOid;
 	RangeVar   *view;
@@ -363,15 +362,12 @@ DefineView(ViewStmt *stmt, const char *queryString)
 	 * Since parse analysis scribbles on its input, copy the raw parse tree;
 	 * this ensures we don't corrupt a prepared statement, for example.
 	 */
-	stmts = parse_analyze((Node *) copyObject(stmt->query),
+	viewParse = parse_analyze((Node *) copyObject(stmt->query),
 							  queryString, NULL, 0);
 
 	/*
 	 * The grammar should ensure that the result is a single SELECT Query.
 	 */
-	if (list_length(stmts) != 1)
-		elog(ERROR, "unexpected parse analysis result");
-	viewParse = (Query *) linitial(stmts);
 	if (!IsA(viewParse, Query) ||
 		viewParse->commandType != CMD_SELECT)
 		elog(ERROR, "unexpected parse analysis result");

src/backend/nodes/makefuncs.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/makefuncs.c,v 1.55 2007/03/17 00:11:03 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/makefuncs.c,v 1.56 2007/06/23 22:12:50 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -134,6 +134,20 @@ flatCopyTargetEntry(TargetEntry *src_tle)
 	return tle;
 }
 
+/*
+ * makeFromExpr -
+ *	  creates a FromExpr node
+ */
+FromExpr *
+makeFromExpr(List *fromlist, Node *quals)
+{
+	FromExpr   *f = makeNode(FromExpr);
+
+	f->fromlist = fromlist;
+	f->quals = quals;
+	return f;
+}
+
 /*
  * makeConst -
  *	  creates a Const node

src/backend/optimizer/util/clauses.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.246 2007/06/11 01:16:23 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/util/clauses.c,v 1.247 2007/06/23 22:12:50 tgl Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -2910,7 +2910,6 @@ inline_function(Oid funcid, Oid result_type, List *args,
 	MemoryContext mycxt;
 	ErrorContextCallback sqlerrcontext;
 	List	   *raw_parsetree_list;
-	List	   *querytree_list;
 	Query	   *querytree;
 	Node	   *newexpr;
 	int		   *usecounts;
@@ -2986,14 +2985,9 @@ inline_function(Oid funcid, Oid result_type, List *args,
 	if (list_length(raw_parsetree_list) != 1)
 		goto fail;
 
-	querytree_list = parse_analyze(linitial(raw_parsetree_list), src,
+	querytree = parse_analyze(linitial(raw_parsetree_list), src,
 							  argtypes, funcform->pronargs);
 
-	if (list_length(querytree_list) != 1)
-		goto fail;
-
-	querytree = (Query *) linitial(querytree_list);
-
 	/*
 	 * The single command must be a simple "SELECT expression".
 	 */
@@ -3025,7 +3019,7 @@ inline_function(Oid funcid, Oid result_type, List *args,
 	 * no rewriting was needed; that's probably not important, but let's be
 	 * careful.
 	 */
-	if (check_sql_fn_retval(funcid, result_type, querytree_list, NULL))
+	if (check_sql_fn_retval(funcid, result_type, list_make1(querytree), NULL))
 		goto fail;				/* reject whole-tuple-result cases */
 
 	/*

src/backend/parser/Makefile

@@ -2,7 +2,7 @@
 #
 # Makefile for parser
 #
-# $PostgreSQL: pgsql/src/backend/parser/Makefile,v 1.44 2006/05/27 17:38:45 tgl Exp $
+# $PostgreSQL: pgsql/src/backend/parser/Makefile,v 1.45 2007/06/23 22:12:51 tgl Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -14,7 +14,7 @@ override CPPFLAGS := -I$(srcdir) $(CPPFLAGS)
 
 OBJS= analyze.o gram.o keywords.o parser.o parse_agg.o parse_clause.o \
       parse_expr.o parse_func.o parse_node.o parse_oper.o parse_relation.o \
-      parse_type.o parse_coerce.o parse_target.o scansup.o
+      parse_type.o parse_coerce.o parse_target.o parse_utilcmd.o scansup.o
 
 FLEXFLAGS = -CF
 

src/backend/parser/README

@@ -1,20 +1,21 @@
 This directory does more than tokenize and parse SQL queries.  It also
-creates Query structures for the various complex queries that is passed
+creates Query structures for the various complex queries that are passed
 to the optimizer and then executor.
 
 parser.c	things start here
 scan.l		break query into tokens
-scansup.c	handle escapes in input
+scansup.c	handle escapes in input strings
 keywords.c	turn keywords into specific tokens
 gram.y		parse the tokens and fill query-type-specific structures
-analyze.c	handle post-parse processing for each query type
+analyze.c	top level of parse analysis for optimizable queries
 parse_clause.c	handle clauses like WHERE, ORDER BY, GROUP BY, ...
-parse_coerce.c	used for coercing expressions of different types
+parse_coerce.c	handle coercing expressions to different types
 parse_expr.c	handle expressions like col, col + 3, x = 3 or x = 4
-parse_oper.c	handle operations in expressions
+parse_oper.c	handle operators in expressions
 parse_agg.c	handle aggregates, like SUM(col1),  AVG(col2), ...
 parse_func.c	handle functions, table.column and column identifiers
 parse_node.c	create nodes for various structures
 parse_target.c	handle the result list of the query
 parse_relation.c support routines for tables and column handling
 parse_type.c	support routines for type handling
+parse_utilcmd.c	parse analysis for utility commands (done at execution time)

src/backend/parser/gram.y

@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.595 2007/06/18 21:40:57 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.596 2007/06/23 22:12:51 tgl Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -33,7 +33,7 @@
  *			SET SQL_inheritance TO off; SELECT * FROM foo;
  *	  because the entire string is parsed by gram.y before the SET gets
  *	  executed.  Anything that depends on the database or changeable state
- *	  should be handled inside parse_analyze() so that it happens at the
+ *	  should be handled during parse analysis so that it happens at the
  *	  right time not the wrong time.  The handling of SQL_inheritance is
  *	  a good example.
  *
@@ -2093,9 +2093,10 @@ ColConstraintElem:
  * ConstraintAttr represents constraint attributes, which we parse as if
  * they were independent constraint clauses, in order to avoid shift/reduce
  * conflicts (since NOT might start either an independent NOT NULL clause
- * or an attribute).  analyze.c is responsible for attaching the attribute
- * information to the preceding "real" constraint node, and for complaining
- * if attribute clauses appear in the wrong place or wrong combinations.
+ * or an attribute).  parse_utilcmd.c is responsible for attaching the
+ * attribute information to the preceding "real" constraint node, and for
+ * complaining if attribute clauses appear in the wrong place or wrong
+ * combinations.
  *
  * See also ConstraintAttributeSpec, which can be used in places where
  * there is no parsing conflict.

src/backend/parser/parse_clause.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/parse_clause.c,v 1.165 2007/04/27 22:05:48 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/parse_clause.c,v 1.166 2007/06/23 22:12:51 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -152,8 +152,8 @@ setTargetTable(ParseState *pstate, RangeVar *relation,
 	 * Open target rel and grab suitable lock (which we will hold till end of
 	 * transaction).
 	 *
-	 * analyze.c will eventually do the corresponding heap_close(), but *not*
-	 * release the lock.
+	 * free_parsestate() will eventually do the corresponding
+	 * heap_close(), but *not* release the lock.
 	 */
 	pstate->p_target_relation = heap_openrv(relation, RowExclusiveLock);
 
@@ -193,7 +193,7 @@ setTargetTable(ParseState *pstate, RangeVar *relation,
  * Simplify InhOption (yes/no/default) into boolean yes/no.
  *
  * The reason we do things this way is that we don't want to examine the
- * SQL_inheritance option flag until parse_analyze is run.	Otherwise,
+ * SQL_inheritance option flag until parse_analyze() is run.	Otherwise,
  * we'd do the wrong thing with query strings that intermix SET commands
  * with queries.
  */
@@ -417,7 +417,6 @@ transformTableEntry(ParseState *pstate, RangeVar *r)
 static RangeTblEntry *
 transformRangeSubselect(ParseState *pstate, RangeSubselect *r)
 {
-	List	   *parsetrees;
 	Query	   *query;
 	RangeTblEntry *rte;
 
@@ -434,19 +433,12 @@ transformRangeSubselect(ParseState *pstate, RangeSubselect *r)
 	/*
 	 * Analyze and transform the subquery.
 	 */
-	parsetrees = parse_sub_analyze(r->subquery, pstate);
+	query = parse_sub_analyze(r->subquery, pstate);
 
 	/*
-	 * Check that we got something reasonable.	Most of these conditions are
-	 * probably impossible given restrictions of the grammar, but check 'em
-	 * anyway.
+	 * Check that we got something reasonable.	Many of these conditions are
+	 * impossible given restrictions of the grammar, but check 'em anyway.
 	 */
-	if (list_length(parsetrees) != 1)
-		elog(ERROR, "unexpected parse analysis result for subquery in FROM");
-	query = (Query *) linitial(parsetrees);
-	if (query == NULL || !IsA(query, Query))
-		elog(ERROR, "unexpected parse analysis result for subquery in FROM");
-
 	if (query->commandType != CMD_SELECT ||
 		query->utilityStmt != NULL)
 		elog(ERROR, "expected SELECT query from subquery in FROM");

src/backend/parser/parse_expr.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/parse_expr.c,v 1.220 2007/06/11 22:22:42 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/parse_expr.c,v 1.221 2007/06/23 22:12:51 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1120,19 +1120,15 @@ transformCaseExpr(ParseState *pstate, CaseExpr *c)
 static Node *
 transformSubLink(ParseState *pstate, SubLink *sublink)
 {
-	List	   *qtrees;
-	Query	   *qtree;
 	Node	   *result = (Node *) sublink;
+	Query	   *qtree;
 
 	/* If we already transformed this node, do nothing */
 	if (IsA(sublink->subselect, Query))
 		return result;
 
 	pstate->p_hasSubLinks = true;
-	qtrees = parse_sub_analyze(sublink->subselect, pstate);
-	if (list_length(qtrees) != 1)
-		elog(ERROR, "bad query in sub-select");
-	qtree = (Query *) linitial(qtrees);
+	qtree = parse_sub_analyze(sublink->subselect, pstate);
 	if (qtree->commandType != CMD_SELECT ||
 		qtree->utilityStmt != NULL ||
 		qtree->intoClause != NULL)

src/backend/parser/parse_node.c

@@ -8,12 +8,13 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/parse_node.c,v 1.97 2007/03/17 00:11:04 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/parse_node.c,v 1.98 2007/06/23 22:12:51 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
 #include "postgres.h"
 
+#include "access/heapam.h"
 #include "catalog/pg_type.h"
 #include "mb/pg_wchar.h"
 #include "nodes/makefuncs.h"
@@ -27,9 +28,11 @@
 #include "utils/varbit.h"
 
 
-/* make_parsestate()
+/*
+ * make_parsestate
  *		Allocate and initialize a new ParseState.
- * The CALLER is responsible for freeing the ParseState* returned.
+ *
+ * Caller should eventually release the ParseState via free_parsestate().
  */
 ParseState *
 make_parsestate(ParseState *parentParseState)
@@ -52,6 +55,30 @@ make_parsestate(ParseState *parentParseState)
 	return pstate;
 }
 
+/*
+ * free_parsestate
+ *		Release a ParseState and any subsidiary resources.
+ */
+void
+free_parsestate(ParseState *pstate)
+{
+	/*
+	 * Check that we did not produce too many resnos; at the very least we
+	 * cannot allow more than 2^16, since that would exceed the range of a
+	 * AttrNumber. It seems safest to use MaxTupleAttributeNumber.
+	 */
+	if (pstate->p_next_resno - 1 > MaxTupleAttributeNumber)
+		ereport(ERROR,
+				(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
+				 errmsg("target lists can have at most %d entries",
+						MaxTupleAttributeNumber)));
+
+	if (pstate->p_target_relation != NULL)
+		heap_close(pstate->p_target_relation, NoLock);
+
+	pfree(pstate);
+}
+
 
 /*
  * parser_errposition

src/backend/rewrite/rewriteDefine.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/rewrite/rewriteDefine.c,v 1.120 2007/04/27 22:05:48 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/rewrite/rewriteDefine.c,v 1.121 2007/06/23 22:12:51 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -20,8 +20,8 @@
 #include "catalog/pg_rewrite.h"
 #include "miscadmin.h"
 #include "optimizer/clauses.h"
-#include "parser/analyze.h"
 #include "parser/parse_expr.h"
+#include "parser/parse_utilcmd.h"
 #include "rewrite/rewriteDefine.h"
 #include "rewrite/rewriteManip.h"
 #include "rewrite/rewriteSupport.h"
@@ -191,7 +191,7 @@ DefineRule(RuleStmt *stmt, const char *queryString)
 	Node	   *whereClause;
 
 	/* Parse analysis ... */
-	analyzeRuleStmt(stmt, queryString, &actions, &whereClause);
+	transformRuleStmt(stmt, queryString, &actions, &whereClause);
 
 	/* ... and execution */
 	DefineQueryRewrite(stmt->rulename,

src/backend/tcop/postgres.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/tcop/postgres.c,v 1.533 2007/04/30 16:37:08 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/tcop/postgres.c,v 1.534 2007/06/23 22:12:52 tgl Exp $
  *
  * NOTES
  *	  this is the "main" module of the postgres backend and
@@ -165,7 +165,7 @@ static int	UseNewLine = 0;		/* Use EOF as query delimiters */
 static int	InteractiveBackend(StringInfo inBuf);
 static int	SocketBackend(StringInfo inBuf);
 static int	ReadCommand(StringInfo inBuf);
-static List *pg_rewrite_queries(List *querytree_list);
+static List *pg_rewrite_query(Query *query);
 static bool check_log_statement(List *stmt_list);
 static int	errdetail_execute(List *raw_parsetree_list);
 static int	errdetail_params(ParamListInfo params);
@@ -567,6 +567,7 @@ List *
 pg_analyze_and_rewrite(Node *parsetree, const char *query_string,
 					   Oid *paramTypes, int numParams)
 {
+	Query	   *query;
 	List	   *querytree_list;
 
 	/*
@@ -575,8 +576,7 @@ pg_analyze_and_rewrite(Node *parsetree, const char *query_string,
 	if (log_parser_stats)
 		ResetUsage();
 
-	querytree_list = parse_analyze(parsetree, query_string,
-								   paramTypes, numParams);
+	query = parse_analyze(parsetree, query_string, paramTypes, numParams);
 
 	if (log_parser_stats)
 		ShowUsage("PARSE ANALYSIS STATISTICS");
@@ -584,68 +584,55 @@ pg_analyze_and_rewrite(Node *parsetree, const char *query_string,
 	/*
 	 * (2) Rewrite the queries, as necessary
 	 */
-	querytree_list = pg_rewrite_queries(querytree_list);
+	querytree_list = pg_rewrite_query(query);
 
 	return querytree_list;
 }
 
 /*
- * Perform rewriting of a list of queries produced by parse analysis.
+ * Perform rewriting of a query produced by parse analysis.
  *
- * Note: queries must just have come from the parser, because we do not do
- * AcquireRewriteLocks() on them.
+ * Note: query must just have come from the parser, because we do not do
+ * AcquireRewriteLocks() on it.
  */
 static List *
-pg_rewrite_queries(List *querytree_list)
+pg_rewrite_query(Query *query)
 {
-	List	   *new_list = NIL;
-	ListCell   *list_item;
+	List	   *querytree_list;
 
 	if (log_parser_stats)
 		ResetUsage();
 
-	/*
-	 * rewritten queries are collected in new_list.  Note there may be more or
-	 * fewer than in the original list.
-	 */
-	foreach(list_item, querytree_list)
-	{
-		Query	   *querytree = (Query *) lfirst(list_item);
-
 	if (Debug_print_parse)
-			elog_node_display(DEBUG1, "parse tree", querytree,
+		elog_node_display(DEBUG1, "parse tree", query,
 						  Debug_pretty_print);
 
-		if (querytree->commandType == CMD_UTILITY)
+	if (query->commandType == CMD_UTILITY)
 	{
-			/* don't rewrite utilities, just dump 'em into new_list */
-			new_list = lappend(new_list, querytree);
+		/* don't rewrite utilities, just dump 'em into result list */
+		querytree_list = list_make1(query);
 	}
 	else
 	{
 		/* rewrite regular queries */
-			List	   *rewritten = QueryRewrite(querytree);
-
-			new_list = list_concat(new_list, rewritten);
-		}
+		querytree_list = QueryRewrite(query);
 	}
 
-	querytree_list = new_list;
-
 	if (log_parser_stats)
 		ShowUsage("REWRITER STATISTICS");
 
 #ifdef COPY_PARSE_PLAN_TREES
+	/* Optional debugging check: pass querytree output through copyObject() */
+	{
+		List	   *new_list;
 
-	/*
-	 * Optional debugging check: pass querytree output through copyObject()
-	 */
 		new_list = (List *) copyObject(querytree_list);
 		/* This checks both copyObject() and the equal() routines... */
 		if (!equal(new_list, querytree_list))
-		elog(WARNING, "copyObject() failed to produce an equal parse tree");
+			elog(WARNING, "copyObject() failed to produce equal parse tree");
 		else
 			querytree_list = new_list;
+	}
 #endif
 
 	if (Debug_print_rewritten)
@@ -1139,6 +1126,7 @@ exec_parse_message(const char *query_string,	/* string to execute */
 
 	if (parsetree_list != NIL)
 	{
+		Query	   *query;
 		int			i;
 
 		raw_parse_tree = (Node *) linitial(parsetree_list);
@@ -1175,7 +1163,7 @@ exec_parse_message(const char *query_string,	/* string to execute */
 		if (log_parser_stats)
 			ResetUsage();
 
-		querytree_list = parse_analyze_varparams(copyObject(raw_parse_tree),
+		query = parse_analyze_varparams(copyObject(raw_parse_tree),
 										query_string,
 										&paramTypes,
 										&numParams);
@@ -1197,7 +1185,7 @@ exec_parse_message(const char *query_string,	/* string to execute */
 		if (log_parser_stats)
 			ShowUsage("PARSE ANALYSIS STATISTICS");
 
-		querytree_list = pg_rewrite_queries(querytree_list);
+		querytree_list = pg_rewrite_query(query);
 
 		/*
 		 * If this is the unnamed statement and it has parameters, defer query

src/backend/tcop/utility.c

@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/tcop/utility.c,v 1.280 2007/05/30 20:12:01 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/tcop/utility.c,v 1.281 2007/06/23 22:12:52 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -45,7 +45,7 @@
 #include "commands/vacuum.h"
 #include "commands/view.h"
 #include "miscadmin.h"
-#include "parser/analyze.h"
+#include "parser/parse_utilcmd.h"
 #include "postmaster/bgwriter.h"
 #include "rewrite/rewriteDefine.h"
 #include "rewrite/rewriteRemove.h"
@@ -544,18 +544,48 @@ ProcessUtility(Node *parsetree,
 
 		case T_CreateStmt:
 			{
+				List		*stmts;
+				ListCell	*l;
 				Oid			relOid;
 
-				relOid = DefineRelation((CreateStmt *) parsetree,
+				/* Run parse analysis ... */
+				stmts = transformCreateStmt((CreateStmt *) parsetree,
+											queryString);
+
+				/* ... and do it */
+				foreach(l, stmts)
+				{
+					Node   *stmt = (Node *) lfirst(l);
+
+					if (IsA(stmt, CreateStmt))
+					{
+						/* Create the table itself */
+						relOid = DefineRelation((CreateStmt *) stmt,
 												RELKIND_RELATION);
 
 						/*
-				 * Let AlterTableCreateToastTable decide if this one needs a
-				 * secondary relation too.
+						 * Let AlterTableCreateToastTable decide if this one
+						 * needs a secondary relation too.
 						 */
 						CommandCounterIncrement();
 						AlterTableCreateToastTable(relOid);
 					}
+					else
+					{
+						/* Recurse for anything else */
+						ProcessUtility(stmt,
+									   queryString,
+									   params,
+									   false,
+									   None_Receiver,
+									   NULL);
+					}
+
+					/* Need CCI between commands */
+					if (lnext(l) != NULL)
+						CommandCounterIncrement();
+				}
+			}
 			break;
 
 		case T_CreateTableSpaceStmt:
@@ -693,7 +723,40 @@ ProcessUtility(Node *parsetree,
 			break;
 
 		case T_AlterTableStmt:
-			AlterTable((AlterTableStmt *) parsetree);
+			{
+				List		*stmts;
+				ListCell	*l;
+
+				/* Run parse analysis ... */
+				stmts = transformAlterTableStmt((AlterTableStmt *) parsetree,
+												queryString);
+
+				/* ... and do it */
+				foreach(l, stmts)
+				{
+					Node   *stmt = (Node *) lfirst(l);
+
+					if (IsA(stmt, AlterTableStmt))
+					{
+						/* Do the table alteration proper */
+						AlterTable((AlterTableStmt *) stmt);
+					}
+					else
+					{
+						/* Recurse for anything else */
+						ProcessUtility(stmt,
+									   queryString,
+									   params,
+									   false,
+									   None_Receiver,
+									   NULL);
+					}
+
+					/* Need CCI between commands */
+					if (lnext(l) != NULL)
+						CommandCounterIncrement();
+				}
+			}
 			break;
 
 		case T_AlterDomainStmt:
@@ -812,7 +875,7 @@ ProcessUtility(Node *parsetree,
 				CheckRelationOwnership(stmt->relation, true);
 
 				/* Run parse analysis ... */
-				stmt = analyzeIndexStmt(stmt, queryString);
+				stmt = transformIndexStmt(stmt, queryString);
 
 				/* ... and do it */
 				DefineIndex(stmt->relation,		/* relation */
@@ -1605,7 +1668,7 @@ CreateCommandTag(Node *parsetree)
 
 				/*
 				 * We might be supporting ALTER INDEX here, so set the
-				 * completion table appropriately. Catch all other
+				 * completion tag appropriately. Catch all other
 				 * possibilities with ALTER TABLE
 				 */
 

src/include/nodes/makefuncs.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/makefuncs.h,v 1.58 2007/03/17 00:11:05 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/makefuncs.h,v 1.59 2007/06/23 22:12:52 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -36,6 +36,8 @@ extern TargetEntry *makeTargetEntry(Expr *expr,
 
 extern TargetEntry *flatCopyTargetEntry(TargetEntry *src_tle);
 
+extern FromExpr *makeFromExpr(List *fromlist, Node *quals);
+
 extern Const *makeConst(Oid consttype,
 		  int32 consttypmod,
 		  int constlen,

src/include/nodes/parsenodes.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.348 2007/04/27 22:05:49 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.349 2007/06/23 22:12:52 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -21,7 +21,7 @@
 typedef enum QuerySource
 {
 	QSRC_ORIGINAL,				/* original parsetree (explicit query) */
-	QSRC_PARSER,				/* added by parse analysis */
+	QSRC_PARSER,				/* added by parse analysis (now unused) */
 	QSRC_INSTEAD_RULE,			/* added by unconditional INSTEAD rule */
 	QSRC_QUAL_INSTEAD_RULE,		/* added by conditional INSTEAD rule */
 	QSRC_NON_INSTEAD_RULE		/* added by non-INSTEAD rule */
@@ -799,10 +799,12 @@ typedef struct SetOperationStmt
 /*****************************************************************************
  *		Other Statements (no optimizations required)
  *
- *		Some of them require a little bit of transformation (which is also
- *		done by transformStmt). The whole structure is then passed on to
- *		ProcessUtility (by-passing the optimization step) as the utilityStmt
- *		field in Query.
+ *		These are not touched by parser/analyze.c except to put them into
+ *		the utilityStmt field of a Query.  This is eventually passed to
+ *		ProcessUtility (by-passing rewriting and planning).  Some of the
+ *		statements do need attention from parse analysis, and this is
+ *		done by routines in parser/parse_utilcmd.c after ProcessUtility
+ *		receives the command for execution.
  *****************************************************************************/
 
 /*
@@ -886,7 +888,7 @@ typedef enum AlterTableType
 	AT_ReAddIndex,				/* internal to commands/tablecmds.c */
 	AT_AddConstraint,			/* add constraint */
 	AT_ProcessedConstraint,		/* pre-processed add constraint (local in
-								 * parser/analyze.c) */
+								 * parser/parse_utilcmd.c) */
 	AT_DropConstraint,			/* drop constraint */
 	AT_DropConstraintQuietly,	/* drop constraint, no error/warning (local in
 								 * commands/tablecmds.c) */
@@ -1083,7 +1085,7 @@ typedef struct CreateStmt
  * relation).  We should never have both in the same node!
  *
  * Constraint attributes (DEFERRABLE etc) are initially represented as
- * separate Constraint nodes for simplicity of parsing.  analyze.c makes
+ * separate Constraint nodes for simplicity of parsing.  parse_utilcmd.c makes
  * a pass through the constraints list to attach the info to the appropriate
  * FkConstraint node (and, perhaps, someday to other kinds of constraints).
  * ----------

src/include/parser/analyze.h

@@ -1,12 +1,13 @@
 /*-------------------------------------------------------------------------
  *
  * analyze.h
+ *		parse analysis for optimizable statements
  *
  *
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/parser/analyze.h,v 1.36 2007/03/13 00:33:43 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/parser/analyze.h,v 1.37 2007/06/23 22:12:52 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -16,16 +17,14 @@
 #include "parser/parse_node.h"
 
 
-extern List *parse_analyze(Node *parseTree, const char *sourceText,
+extern Query *parse_analyze(Node *parseTree, const char *sourceText,
 			  Oid *paramTypes, int numParams);
-extern List *parse_analyze_varparams(Node *parseTree, const char *sourceText,
+extern Query *parse_analyze_varparams(Node *parseTree, const char *sourceText,
 						Oid **paramTypes, int *numParams);
-extern List *parse_sub_analyze(Node *parseTree, ParseState *parentParseState);
 
-extern IndexStmt *analyzeIndexStmt(IndexStmt *stmt, const char *queryString);
-extern void analyzeRuleStmt(RuleStmt *stmt, const char *queryString,
-				List **actions, Node **whereClause);
-extern List *analyzeCreateSchemaStmt(CreateSchemaStmt *stmt);
+extern Query *parse_sub_analyze(Node *parseTree, ParseState *parentParseState);
+extern Query *transformStmt(ParseState *pstate, Node *parseTree);
+
 extern void CheckSelectLocking(Query *qry);
 extern void applyLockingClause(Query *qry, Index rtindex,
 				   bool forUpdate, bool noWait);

src/include/parser/parse_node.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/parser/parse_node.h,v 1.51 2007/01/05 22:19:57 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/parser/parse_node.h,v 1.52 2007/06/23 22:12:52 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -83,6 +83,7 @@ typedef struct ParseState
 } ParseState;
 
 extern ParseState *make_parsestate(ParseState *parentParseState);
+extern void free_parsestate(ParseState *pstate);
 extern int	parser_errposition(ParseState *pstate, int location);
 
 extern Var *make_var(ParseState *pstate, RangeTblEntry *rte, int attrno);

src/include/parser/parse_utilcmd.h

@@ -0,0 +1,28 @@
+/*-------------------------------------------------------------------------
+ *
+ * parse_utilcmd.h
+ *		parse analysis for utility commands
+ *
+ *
+ * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * $PostgreSQL: pgsql/src/include/parser/parse_utilcmd.h,v 1.1 2007/06/23 22:12:52 tgl Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef PARSE_UTILCMD_H
+#define PARSE_UTILCMD_H
+
+#include "parser/parse_node.h"
+
+
+extern List *transformCreateStmt(CreateStmt *stmt, const char *queryString);
+extern List *transformAlterTableStmt(AlterTableStmt *stmt,
+									 const char *queryString);
+extern IndexStmt *transformIndexStmt(IndexStmt *stmt, const char *queryString);
+extern void transformRuleStmt(RuleStmt *stmt, const char *queryString,
+							  List **actions, Node **whereClause);
+extern List *transformCreateSchemaStmt(CreateSchemaStmt *stmt);
+
+#endif   /* PARSE_UTILCMD_H */