Repair some issues with column aliases and RowExpr construction in the

presence of dropped columns.  Document the already-presumed fact that
eref aliases in relation RTEs are supposed to have entries for dropped
columns; cause the user alias structs to have such entries too, so that
there's always a one-to-one mapping to the underlying physical attnums.
Adjust expandRTE() and related code to handle the case where a column
that is part of a JOIN has been dropped.  Generalize expandRTE()'s API
so that it can be used in a couple of places that formerly rolled their
own implementation of the same logic.  Fix ruleutils.c to suppress
display of aliases for columns that were dropped since the rule was made.

src/backend/catalog/dependency.c

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/catalog/dependency.c,v 1.36 2004/05/26 04:41:06 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/backend/catalog/dependency.c,v 1.37 2004/08/19 20:57:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -970,10 +970,15 @@ find_expr_references_walker(Node *node,
 		if (var->varno <= 0 || var->varno > list_length(rtable))
 			elog(ERROR, "invalid varno %d", var->varno);
 		rte = rt_fetch(var->varno, rtable);
+		/*
+		 * A whole-row Var references no specific columns, so adds no new
+		 * dependency.
+		 */
+		if (var->varattno == InvalidAttrNumber)
+			return false;
 		if (rte->rtekind == RTE_RELATION)
 		{
 			/* If it's a plain relation, reference this column */
-			/* NB: this code works for whole-row Var with attno 0, too */
 			add_object_address(OCLASS_CLASS, rte->relid, var->varattno,
 							   &context->addrs);
 		}

src/backend/optimizer/path/allpaths.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/path/allpaths.c,v 1.118 2004/06/05 01:55:04 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/path/allpaths.c,v 1.119 2004/08/19 20:57:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -57,10 +57,10 @@ static void compare_tlist_datatypes(List *tlist, List *colTypes,
 						bool *differentTypes);
 static bool qual_is_pushdown_safe(Query *subquery, Index rti, Node *qual,
 					  bool *differentTypes);
-static void subquery_push_qual(Query *subquery,
-							   RangeTblEntry *rte, Index rti, Node *qual);
+static void subquery_push_qual(Query *subquery, List *rtable,
+							   Index rti, Node *qual);
 static void recurse_push_qual(Node *setOp, Query *topquery,
-							  RangeTblEntry *rte, Index rti, Node *qual);
+							  List *rtable, Index rti, Node *qual);
 
 
 /*
@@ -376,7 +376,7 @@ set_subquery_pathlist(Query *root, RelOptInfo *rel,
 			if (qual_is_pushdown_safe(subquery, rti, clause, differentTypes))
 			{
 				/* Push it down */
-				subquery_push_qual(subquery, rte, rti, clause);
+				subquery_push_qual(subquery, root->rtable, rti, clause);
 			}
 			else
 			{
@@ -780,12 +780,13 @@ qual_is_pushdown_safe(Query *subquery, Index rti, Node *qual,
  * subquery_push_qual - push down a qual that we have determined is safe
  */
 static void
-subquery_push_qual(Query *subquery, RangeTblEntry *rte, Index rti, Node *qual)
+subquery_push_qual(Query *subquery, List *rtable, Index rti, Node *qual)
 {
 	if (subquery->setOperations != NULL)
 	{
 		/* Recurse to push it separately to each component query */
-		recurse_push_qual(subquery->setOperations, subquery, rte, rti, qual);
+		recurse_push_qual(subquery->setOperations, subquery,
+						  rtable, rti, qual);
 	}
 	else
 	{
@@ -799,7 +800,7 @@ subquery_push_qual(Query *subquery, RangeTblEntry *rte, Index rti, Node *qual)
 		 * This step also ensures that when we are pushing into a setop tree,
 		 * each component query gets its own copy of the qual.
 		 */
-		qual = ResolveNew(qual, rti, 0, rte,
+		qual = ResolveNew(qual, rti, 0, rtable,
 						  subquery->targetList,
 						  CMD_SELECT, 0);
 		subquery->havingQual = make_and_qual(subquery->havingQual,
@@ -818,7 +819,7 @@ subquery_push_qual(Query *subquery, RangeTblEntry *rte, Index rti, Node *qual)
  */
 static void
 recurse_push_qual(Node *setOp, Query *topquery,
-				  RangeTblEntry *rte, Index rti, Node *qual)
+				  List *rtable, Index rti, Node *qual)
 {
 	if (IsA(setOp, RangeTblRef))
 	{
@@ -827,14 +828,14 @@ recurse_push_qual(Node *setOp, Query *topquery,
 		Query	   *subquery = subrte->subquery;
 
 		Assert(subquery != NULL);
-		subquery_push_qual(subquery, rte, rti, qual);
+		subquery_push_qual(subquery, rtable, rti, qual);
 	}
 	else if (IsA(setOp, SetOperationStmt))
 	{
 		SetOperationStmt *op = (SetOperationStmt *) setOp;
 
-		recurse_push_qual(op->larg, topquery, rte, rti, qual);
-		recurse_push_qual(op->rarg, topquery, rte, rti, qual);
+		recurse_push_qual(op->larg, topquery, rtable, rti, qual);
+		recurse_push_qual(op->rarg, topquery, rtable, rti, qual);
 	}
 	else
 	{

src/backend/optimizer/prep/prepjointree.c

@@ -16,7 +16,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/prep/prepjointree.c,v 1.20 2004/05/30 23:40:29 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/prep/prepjointree.c,v 1.21 2004/08/19 20:57:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -46,7 +46,7 @@ typedef struct reduce_outer_joins_state
 static bool is_simple_subquery(Query *subquery);
 static bool has_nullable_targetlist(Query *subquery);
 static void resolvenew_in_jointree(Node *jtnode, int varno,
-								   RangeTblEntry *rte, List *subtlist);
+								   List *rtable, List *subtlist);
 static reduce_outer_joins_state *reduce_outer_joins_pass1(Node *jtnode);
 static void reduce_outer_joins_pass2(Node *jtnode,
 						 reduce_outer_joins_state *state,
@@ -243,16 +243,19 @@ pull_up_subqueries(Query *parse, Node *jtnode, bool below_outer_join)
 			subtlist = subquery->targetList;
 			parse->targetList = (List *)
 				ResolveNew((Node *) parse->targetList,
-						   varno, 0, rte, subtlist, CMD_SELECT, 0);
+						   varno, 0, parse->rtable,
+						   subtlist, CMD_SELECT, 0);
 			resolvenew_in_jointree((Node *) parse->jointree, varno,
-								   rte, subtlist);
+								   parse->rtable, subtlist);
 			Assert(parse->setOperations == NULL);
 			parse->havingQual =
 				ResolveNew(parse->havingQual,
-						   varno, 0, rte, subtlist, CMD_SELECT, 0);
+						   varno, 0, parse->rtable,
+						   subtlist, CMD_SELECT, 0);
 			parse->in_info_list = (List *)
 				ResolveNew((Node *) parse->in_info_list,
-						   varno, 0, rte, subtlist, CMD_SELECT, 0);
+						   varno, 0, parse->rtable,
+						   subtlist, CMD_SELECT, 0);
 
 			foreach(rt, parse->rtable)
 			{
@@ -261,7 +264,8 @@ pull_up_subqueries(Query *parse, Node *jtnode, bool below_outer_join)
 				if (otherrte->rtekind == RTE_JOIN)
 					otherrte->joinaliasvars = (List *)
 						ResolveNew((Node *) otherrte->joinaliasvars,
-								   varno, 0, rte, subtlist, CMD_SELECT, 0);
+								   varno, 0, parse->rtable,
+								   subtlist, CMD_SELECT, 0);
 			}
 
 			/*
@@ -477,7 +481,7 @@ has_nullable_targetlist(Query *subquery)
  */
 static void
 resolvenew_in_jointree(Node *jtnode, int varno,
-					   RangeTblEntry *rte, List *subtlist)
+					   List *rtable, List *subtlist)
 {
 	if (jtnode == NULL)
 		return;
@@ -491,18 +495,20 @@ resolvenew_in_jointree(Node *jtnode, int varno,
 		ListCell   *l;
 
 		foreach(l, f->fromlist)
-			resolvenew_in_jointree(lfirst(l), varno, rte, subtlist);
+			resolvenew_in_jointree(lfirst(l), varno, rtable, subtlist);
 		f->quals = ResolveNew(f->quals,
-							  varno, 0, rte, subtlist, CMD_SELECT, 0);
+							  varno, 0, rtable,
+							  subtlist, CMD_SELECT, 0);
 	}
 	else if (IsA(jtnode, JoinExpr))
 	{
 		JoinExpr   *j = (JoinExpr *) jtnode;
 
-		resolvenew_in_jointree(j->larg, varno, rte, subtlist);
-		resolvenew_in_jointree(j->rarg, varno, rte, subtlist);
+		resolvenew_in_jointree(j->larg, varno, rtable, subtlist);
+		resolvenew_in_jointree(j->rarg, varno, rtable, subtlist);
 		j->quals = ResolveNew(j->quals,
-							  varno, 0, rte, subtlist, CMD_SELECT, 0);
+							  varno, 0, rtable,
+							  subtlist, CMD_SELECT, 0);
 
 		/*
 		 * We don't bother to update the colvars list, since it won't be

src/backend/optimizer/util/var.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/util/var.c,v 1.59 2004/06/01 04:47:46 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/util/var.c,v 1.60 2004/08/19 20:57:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -515,11 +515,19 @@ flatten_join_alias_vars_mutator(Node *node,
 			/* Must expand whole-row reference */
 			RowExpr		*rowexpr;
 			List		*fields = NIL;
+			AttrNumber	attnum;
 			ListCell	*l;
 
+			attnum = 0;
 			foreach(l, rte->joinaliasvars)
 			{
 				newvar = (Node *) lfirst(l);
+				attnum++;
+				/* Ignore dropped columns */
+				if (get_rte_attribute_is_dropped(context->root->rtable,
+												 var->varno,
+												 attnum))
+					continue;
 				/*
 				 * If we are expanding an alias carried down from an upper
 				 * query, must adjust its varlevelsup fields.

src/backend/parser/parse_clause.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/parse_clause.c,v 1.133 2004/06/16 01:26:44 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/parse_clause.c,v 1.134 2004/08/19 20:57:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -655,8 +655,8 @@ transformFromClauseItem(ParseState *pstate, Node *n, List **containedRels)
 			elog(ERROR, "unrecognized node type: %d", (int) nodeTag(j->larg));
 			leftrti = 0;		/* keep compiler quiet */
 		}
-		rte = rt_fetch(leftrti, pstate->p_rtable);
-		expandRTE(pstate, rte, &l_colnames, &l_colvars);
+		expandRTE(pstate->p_rtable, leftrti, 0, false,
+				  &l_colnames, &l_colvars);
 
 		if (IsA(j->rarg, RangeTblRef))
 			rightrti = ((RangeTblRef *) j->rarg)->rtindex;
@@ -667,8 +667,8 @@ transformFromClauseItem(ParseState *pstate, Node *n, List **containedRels)
 			elog(ERROR, "unrecognized node type: %d", (int) nodeTag(j->rarg));
 			rightrti = 0;		/* keep compiler quiet */
 		}
-		rte = rt_fetch(rightrti, pstate->p_rtable);
-		expandRTE(pstate, rte, &r_colnames, &r_colvars);
+		expandRTE(pstate->p_rtable, rightrti, 0, false,
+				  &r_colnames, &r_colvars);
 
 		/*
 		 * Natural join does not explicitly specify columns; must generate

src/backend/parser/parse_coerce.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/parse_coerce.c,v 2.120 2004/08/17 18:47:08 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/parse_coerce.c,v 2.121 2004/08/19 20:57:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -662,29 +662,12 @@ coerce_record_to_complex(ParseState *pstate, Node *node,
 	else if (node && IsA(node, Var) &&
 			 ((Var *) node)->varattno == InvalidAttrNumber)
 	{
-		RangeTblEntry *rte;
-		AttrNumber nfields;
-		AttrNumber nf;
+		int		rtindex = ((Var *) node)->varno;
+		int		sublevels_up = ((Var *) node)->varlevelsup;
+		List *rtable;
 
-		rte = GetRTEByRangeTablePosn(pstate,
-									 ((Var *) node)->varno,
-									 ((Var *) node)->varlevelsup);
-		nfields = list_length(rte->eref->colnames);
-		for (nf = 1; nf <= nfields; nf++)
-		{
-			Oid		vartype;
-			int32	vartypmod;
-
-			if (get_rte_attribute_is_dropped(rte, nf))
-				continue;
-			get_rte_attribute_type(rte, nf, &vartype, &vartypmod);
-			args = lappend(args,
-						   makeVar(((Var *) node)->varno,
-								   nf,
-								   vartype,
-								   vartypmod,
-								   ((Var *) node)->varlevelsup));
-		}
+		rtable = GetLevelNRangeTable(pstate, sublevels_up);
+		expandRTE(rtable, rtindex, sublevels_up, false, NULL, &args);
 	}
 	else
 		ereport(ERROR,

src/backend/parser/parse_relation.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/parse_relation.c,v 1.97 2004/08/17 18:47:08 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/parse_relation.c,v 1.98 2004/08/19 20:57:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -42,6 +42,10 @@ static Node *scanNameSpaceForRelid(ParseState *pstate, Node *nsnode,
 static void scanNameSpaceForConflict(ParseState *pstate, Node *nsnode,
 						 RangeTblEntry *rte1, const char *aliasname1);
 static bool isForUpdate(ParseState *pstate, char *refname);
+static void expandRelation(Oid relid, Alias *eref,
+						   int rtindex, int sublevels_up,
+						   bool include_dropped,
+						   List **colnames, List **colvars);
 static int	specialAttNum(const char *attname);
 static void warnAutoRange(ParseState *pstate, RangeVar *relation);
 
@@ -438,6 +442,27 @@ GetRTEByRangeTablePosn(ParseState *pstate,
 	return rt_fetch(varno, pstate->p_rtable);
 }
 
+/*
+ * GetLevelNRangeTable
+ *	  Get the rangetable list for the N'th query level up from current.
+ */
+List *
+GetLevelNRangeTable(ParseState *pstate, int sublevels_up)
+{
+	int			index = 0;
+
+	while (pstate != NULL)
+	{
+		if (index == sublevels_up)
+			return pstate->p_rtable;
+		index++;
+		pstate = pstate->parentParseState;
+	}
+
+	elog(ERROR, "rangetable not found (internal error)");
+	return NIL;					/* keep compiler quiet */
+}
+
 /*
  * scanRTEForColumn
  *	  Search the column names of a single RTE for the given name.
@@ -464,27 +489,20 @@ scanRTEForColumn(ParseState *pstate, RangeTblEntry *rte, char *colname)
 	 * Scan the user column names (or aliases) for a match. Complain if
 	 * multiple matches.
 	 *
-	 * Note: because eref->colnames may include names of dropped columns, we
-	 * need to check for non-droppedness before accepting a match. This
-	 * takes an extra cache lookup, but we can skip the lookup most of the
-	 * time by exploiting the knowledge that dropped columns are assigned
-	 * dummy names starting with '.', which is an unusual choice for
-	 * actual column names.
+	 * Note: eref->colnames may include entries for dropped columns,
+	 * but those will be empty strings that cannot match any legal SQL
+	 * identifier, so we don't bother to test for that case here.
 	 *
-	 * Should the user try to fool us by altering pg_attribute.attname for a
-	 * dropped column, we'll still catch it by virtue of the checks in
-	 * get_rte_attribute_type(), which is called by make_var().  That
-	 * routine has to do a cache lookup anyway, so the check there is
-	 * cheap.
+	 * Should this somehow go wrong and we try to access a dropped column,
+	 * we'll still catch it by virtue of the checks in
+	 * get_rte_attribute_type(), which is called by make_var().  That routine
+	 * has to do a cache lookup anyway, so the check there is cheap.
 	 */
 	foreach(c, rte->eref->colnames)
 	{
 		attnum++;
 		if (strcmp(strVal(lfirst(c)), colname) == 0)
 		{
-			if (colname[0] == '.' &&	/* see note above */
-				get_rte_attribute_is_dropped(rte, attnum))
-				continue;
 			if (result)
 				ereport(ERROR,
 						(errcode(ERRCODE_AMBIGUOUS_COLUMN),
@@ -633,6 +651,81 @@ qualifiedNameToVar(ParseState *pstate,
 	return scanRTEForColumn(pstate, rte, colname);
 }
 
+/*
+ * buildRelationAliases
+ *		Construct the eref column name list for a relation RTE.
+ *		This code is also used for the case of a function RTE returning
+ *		a named composite type.
+ *
+ * tupdesc: the physical column information
+ * alias: the user-supplied alias, or NULL if none
+ * eref: the eref Alias to store column names in
+ *
+ * eref->colnames is filled in.  Also, alias->colnames is rebuilt to insert
+ * empty strings for any dropped columns, so that it will be one-to-one with
+ * physical column numbers.
+ */
+static void
+buildRelationAliases(TupleDesc tupdesc, Alias *alias, Alias *eref)
+{
+	int			maxattrs = tupdesc->natts;
+	ListCell   *aliaslc;
+	int			numaliases;
+	int			varattno;
+	int			numdropped = 0;
+
+	Assert(eref->colnames == NIL);
+
+	if (alias)
+	{
+		aliaslc = list_head(alias->colnames);
+		numaliases = list_length(alias->colnames);
+		/* We'll rebuild the alias colname list */
+		alias->colnames = NIL;
+	}
+	else
+	{
+		aliaslc = NULL;
+		numaliases = 0;
+	}
+
+	for (varattno = 0; varattno < maxattrs; varattno++)
+	{
+		Form_pg_attribute attr = tupdesc->attrs[varattno];
+		Value	   *attrname;
+
+		if (attr->attisdropped)
+		{
+			/* Always insert an empty string for a dropped column */
+			attrname = makeString(pstrdup(""));
+			if (aliaslc)
+				alias->colnames = lappend(alias->colnames, attrname);
+			numdropped++;
+		}
+		else if (aliaslc)
+		{
+			/* Use the next user-supplied alias */
+			attrname = (Value *) lfirst(aliaslc);
+			aliaslc = lnext(aliaslc);
+			alias->colnames = lappend(alias->colnames, attrname);
+		}
+		else
+		{
+			attrname = makeString(pstrdup(NameStr(attr->attname)));
+			/* we're done with the alias if any */
+		}
+
+		eref->colnames = lappend(eref->colnames, attrname);
+	}
+
+	/* Too many user-supplied aliases? */
+	if (aliaslc)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
+				 errmsg("table \"%s\" has %d columns available but %d columns specified",
+						eref->aliasname, maxattrs - numdropped, numaliases)));
+}
+
 /*
  * Add an entry for a relation to the pstate's range table (p_rtable).
  *
@@ -653,10 +746,6 @@ addRangeTableEntry(ParseState *pstate,
 	char	   *refname = alias ? alias->aliasname : relation->relname;
 	LOCKMODE	lockmode;
 	Relation	rel;
-	Alias	   *eref;
-	int			maxattrs;
-	int			numaliases;
-	int			varattno;
 
 	rte->rtekind = RTE_RELATION;
 	rte->alias = alias;
@@ -671,29 +760,12 @@ addRangeTableEntry(ParseState *pstate,
 	rel = heap_openrv(relation, lockmode);
 	rte->relid = RelationGetRelid(rel);
 
-	eref = alias ? (Alias *) copyObject(alias) : makeAlias(refname, NIL);
-	numaliases = list_length(eref->colnames);
-
 	/*
-	 * Since the rel is open anyway, let's check that the number of column
-	 * aliases is reasonable. - Thomas 2000-02-04
+	 * Build the list of effective column names using user-supplied aliases
+	 * and/or actual column names.
 	 */
-	maxattrs = RelationGetNumberOfAttributes(rel);
-	if (maxattrs < numaliases)
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
-				 errmsg("table \"%s\" has %d columns available but %d columns specified",
-				   RelationGetRelationName(rel), maxattrs, numaliases)));
-
-	/* fill in any unspecified alias columns using actual column names */
-	for (varattno = numaliases; varattno < maxattrs; varattno++)
-	{
-		char	   *attrname;
-
-		attrname = pstrdup(NameStr(rel->rd_att->attrs[varattno]->attname));
-		eref->colnames = lappend(eref->colnames, makeString(attrname));
-	}
-	rte->eref = eref;
+	rte->eref = makeAlias(refname, NIL);
+	buildRelationAliases(rel->rd_att, alias, rte->eref);
 
 	/*
 	 * Drop the rel refcount, but keep the access lock till end of
@@ -747,10 +819,6 @@ addRangeTableEntryForRelation(ParseState *pstate,
 	char	   *refname = alias->aliasname;
 	LOCKMODE	lockmode;
 	Relation	rel;
-	Alias	   *eref;
-	int			maxattrs;
-	int			numaliases;
-	int			varattno;
 
 	rte->rtekind = RTE_RELATION;
 	rte->alias = alias;
@@ -765,29 +833,12 @@ addRangeTableEntryForRelation(ParseState *pstate,
 	rel = heap_open(relid, lockmode);
 	rte->relid = relid;
 
-	eref = (Alias *) copyObject(alias);
-	numaliases = list_length(eref->colnames);
-
 	/*
-	 * Since the rel is open anyway, let's check that the number of column
-	 * aliases is reasonable. - Thomas 2000-02-04
+	 * Build the list of effective column names using user-supplied aliases
+	 * and/or actual column names.
 	 */
-	maxattrs = RelationGetNumberOfAttributes(rel);
-	if (maxattrs < numaliases)
-		ereport(ERROR,
-				(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
-				 errmsg("table \"%s\" has %d columns available but %d columns specified",
-				   RelationGetRelationName(rel), maxattrs, numaliases)));
-
-	/* fill in any unspecified alias columns using actual column names */
-	for (varattno = numaliases; varattno < maxattrs; varattno++)
-	{
-		char	   *attrname;
-
-		attrname = pstrdup(NameStr(rel->rd_att->attrs[varattno]->attname));
-		eref->colnames = lappend(eref->colnames, makeString(attrname));
-	}
-	rte->eref = eref;
+	rte->eref = makeAlias(refname, NIL);
+	buildRelationAliases(rel->rd_att, alias, rte->eref);
 
 	/*
 	 * Drop the rel refcount, but keep the access lock till end of
@@ -918,8 +969,6 @@ addRangeTableEntryForFunction(ParseState *pstate,
 	Alias	   *alias = rangefunc->alias;
 	List	   *coldeflist = rangefunc->coldeflist;
 	Alias	   *eref;
-	int			numaliases;
-	int			varattno;
 
 	rte->rtekind = RTE_FUNCTION;
 	rte->relid = InvalidOid;
@@ -928,11 +977,9 @@ addRangeTableEntryForFunction(ParseState *pstate,
 	rte->coldeflist = coldeflist;
 	rte->alias = alias;
 
-	eref = alias ? (Alias *) copyObject(alias) : makeAlias(funcname, NIL);
+	eref = makeAlias(alias ? alias->aliasname : funcname, NIL);
 	rte->eref = eref;
 
-	numaliases = list_length(eref->colnames);
-
 	/*
 	 * Now determine if the function returns a simple or composite type,
 	 * and check/add column aliases.
@@ -969,7 +1016,6 @@ addRangeTableEntryForFunction(ParseState *pstate,
 		 */
 		Oid			funcrelid = typeidTypeRelid(funcrettype);
 		Relation	rel;
-		int			maxattrs;
 
 		if (!OidIsValid(funcrelid))		/* shouldn't happen if typtype is
 										 * 'c' */
@@ -981,26 +1027,8 @@ addRangeTableEntryForFunction(ParseState *pstate,
 		 */
 		rel = relation_open(funcrelid, AccessShareLock);
 
-		/*
-		 * Since the rel is open anyway, let's check that the number of
-		 * column aliases is reasonable.
-		 */
-		maxattrs = RelationGetNumberOfAttributes(rel);
-		if (maxattrs < numaliases)
-			ereport(ERROR,
-					(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
-					 errmsg("table \"%s\" has %d columns available but %d columns specified",
-							RelationGetRelationName(rel),
-							maxattrs, numaliases)));
-
-		/* fill in alias columns using actual column names */
-		for (varattno = numaliases; varattno < maxattrs; varattno++)
-		{
-			char	   *attrname;
-
-			attrname = pstrdup(NameStr(rel->rd_att->attrs[varattno]->attname));
-			eref->colnames = lappend(eref->colnames, makeString(attrname));
-		}
+		/* Build the column alias list */
+		buildRelationAliases(rel->rd_att, alias, eref);
 
 		/*
 		 * Drop the rel refcount, but keep the access lock till end of
@@ -1015,12 +1043,16 @@ addRangeTableEntryForFunction(ParseState *pstate,
 		 * Must be a base data type, i.e. scalar. Just add one alias
 		 * column named for the function.
 		 */
-		if (numaliases > 1)
+		if (alias && alias->colnames != NIL)
+		{
+			if (list_length(alias->colnames) != 1)
 				ereport(ERROR,
 						(errcode(ERRCODE_INVALID_COLUMN_REFERENCE),
 						 errmsg("too many column aliases specified for function %s",
 								funcname)));
-		if (numaliases == 0)
+			eref->colnames = copyObject(alias->colnames);
+		}
+		else
 			eref->colnames = list_make1(makeString(eref->aliasname));
 	}
 	else if (functyptype == 'p' && funcrettype == RECORDOID)
@@ -1028,7 +1060,6 @@ addRangeTableEntryForFunction(ParseState *pstate,
 		ListCell   *col;
 
 		/* Use the column definition list to form the alias list */
-		eref->colnames = NIL;
 		foreach(col, coldeflist)
 		{
 			ColumnDef  *n = lfirst(col);
@@ -1202,77 +1233,42 @@ addImplicitRTE(ParseState *pstate, RangeVar *relation)
 	return rte;
 }
 
-/* expandRTE()
+/*
+ * expandRTE -- expand the columns of a rangetable entry
  *
- * Given a rangetable entry, create lists of its column names (aliases if
- * provided, else real names) and Vars for each column.  Only user columns
- * are considered, since this is primarily used to expand '*' and determine
- * the contents of JOIN tables.
+ * This creates lists of an RTE's column names (aliases if provided, else
+ * real names) and Vars for each column.  Only user columns are considered.
+ * If include_dropped is FALSE then dropped columns are omitted from the
+ * results.  If include_dropped is TRUE then empty strings and NULL constants
+ * (not Vars!) are returned for dropped columns.
  *
+ * The target RTE is the rtindex'th entry of rtable.  (The whole rangetable
+ * must be passed since we need it to determine dropped-ness for JOIN columns.)
+ * sublevels_up is the varlevelsup value to use in the created Vars.
+ *
+ * The output lists go into *colnames and *colvars.
  * If only one of the two kinds of output list is needed, pass NULL for the
  * output pointer for the unwanted one.
  */
 void
-expandRTE(ParseState *pstate, RangeTblEntry *rte,
+expandRTE(List *rtable, int rtindex, int sublevels_up,
+		  bool include_dropped,
 		  List **colnames, List **colvars)
 {
-	int			rtindex,
-				sublevels_up,
-				varattno;
+	RangeTblEntry *rte = rt_fetch(rtindex, rtable);
+	int			varattno;
 
 	if (colnames)
 		*colnames = NIL;
 	if (colvars)
 		*colvars = NIL;
 
-	/* Need the RT index of the entry for creating Vars */
-	rtindex = RTERangeTablePosn(pstate, rte, &sublevels_up);
-
 	switch (rte->rtekind)
 	{
 		case RTE_RELATION:
-			{
 			/* Ordinary relation RTE */
-				Relation	rel;
-				int			maxattrs;
-				int			numaliases;
-
-				rel = heap_open(rte->relid, AccessShareLock);
-				maxattrs = RelationGetNumberOfAttributes(rel);
-				numaliases = list_length(rte->eref->colnames);
-
-				for (varattno = 0; varattno < maxattrs; varattno++)
-				{
-					Form_pg_attribute attr = rel->rd_att->attrs[varattno];
-
-					if (attr->attisdropped)
-						continue;
-
-					if (colnames)
-					{
-						char	   *label;
-
-						if (varattno < numaliases)
-							label = strVal(list_nth(rte->eref->colnames, varattno));
-						else
-							label = NameStr(attr->attname);
-						*colnames = lappend(*colnames, makeString(pstrdup(label)));
-					}
-
-					if (colvars)
-					{
-						Var		   *varnode;
-
-						varnode = makeVar(rtindex, attr->attnum,
-										  attr->atttypid, attr->atttypmod,
-										  sublevels_up);
-
-						*colvars = lappend(*colvars, varnode);
-					}
-				}
-
-				heap_close(rel, AccessShareLock);
-			}
+			expandRelation(rte->relid, rte->eref, rtindex, sublevels_up,
+						   include_dropped, colnames, colvars);
 			break;
 		case RTE_SUBQUERY:
 			{
@@ -1318,60 +1314,22 @@ expandRTE(ParseState *pstate, RangeTblEntry *rte,
 				/* Function RTE */
 				Oid			funcrettype = exprType(rte->funcexpr);
 				char		functyptype = get_typtype(funcrettype);
-				List	   *coldeflist = rte->coldeflist;
 
 				if (functyptype == 'c')
 				{
 					/*
-					 * Composite data type, i.e. a table's row type Same
-					 * as ordinary relation RTE
+					 * Composite data type, i.e. a table's row type
+					 *
+					 * Same as ordinary relation RTE
 					 */
 					Oid			funcrelid = typeidTypeRelid(funcrettype);
-					Relation	rel;
-					int			maxattrs;
-					int			numaliases;
 
 					if (!OidIsValid(funcrelid)) /* shouldn't happen */
 						elog(ERROR, "invalid typrelid for complex type %u",
 							 funcrettype);
 
-					rel = relation_open(funcrelid, AccessShareLock);
-					maxattrs = RelationGetNumberOfAttributes(rel);
-					numaliases = list_length(rte->eref->colnames);
-
-					for (varattno = 0; varattno < maxattrs; varattno++)
-					{
-						Form_pg_attribute attr = rel->rd_att->attrs[varattno];
-
-						if (attr->attisdropped)
-							continue;
-
-						if (colnames)
-						{
-							char	   *label;
-
-							if (varattno < numaliases)
-								label = strVal(list_nth(rte->eref->colnames, varattno));
-							else
-								label = NameStr(attr->attname);
-							*colnames = lappend(*colnames, makeString(pstrdup(label)));
-						}
-
-						if (colvars)
-						{
-							Var		   *varnode;
-
-							varnode = makeVar(rtindex,
-											  attr->attnum,
-											  attr->atttypid,
-											  attr->atttypmod,
-											  sublevels_up);
-
-							*colvars = lappend(*colvars, varnode);
-						}
-					}
-
-					relation_close(rel, AccessShareLock);
+					expandRelation(funcrelid, rte->eref, rtindex, sublevels_up,
+								   include_dropped, colnames, colvars);
 				}
 				else if (functyptype == 'b' || functyptype == 'd')
 				{
@@ -1395,6 +1353,7 @@ expandRTE(ParseState *pstate, RangeTblEntry *rte,
 				}
 				else if (functyptype == 'p' && funcrettype == RECORDOID)
 				{
+					List	   *coldeflist = rte->coldeflist;
 					ListCell   *col;
 					int			attnum = 0;
 
@@ -1447,11 +1406,41 @@ expandRTE(ParseState *pstate, RangeTblEntry *rte,
 				{
 					varattno++;
 
+					/*
+					 * During ordinary parsing, there will never be any
+					 * deleted columns in the join; but we have to check
+					 * since this routine is also used by the rewriter,
+					 * and joins found in stored rules might have join
+					 * columns for since-deleted columns.
+					 */
+					if (get_rte_attribute_is_dropped(rtable, rtindex,
+													 varattno))
+					{
+						if (include_dropped)
+						{
+							if (colnames)
+								*colnames = lappend(*colnames,
+													makeString(pstrdup("")));
+							if (colvars)
+							{
+								/*
+								 * can't use atttypid here, but it doesn't
+								 * really matter what type the Const claims to
+								 * be.
+								 */
+								*colvars = lappend(*colvars,
+												   makeNullConst(INT4OID));
+							}
+						}
+						continue;
+					}
+
 					if (colnames)
 					{
 						char	   *label = strVal(lfirst(colname));
 
-						*colnames = lappend(*colnames, makeString(pstrdup(label)));
+						*colnames = lappend(*colnames,
+											makeString(pstrdup(label)));
 					}
 
 					if (colvars)
@@ -1474,13 +1463,78 @@ expandRTE(ParseState *pstate, RangeTblEntry *rte,
 	}
 }
 
+/*
+ * expandRelation -- expandRTE subroutine
+ */
+static void
+expandRelation(Oid relid, Alias *eref, int rtindex, int sublevels_up,
+			   bool include_dropped,
+			   List **colnames, List **colvars)
+{
+	Relation	rel;
+	int			varattno;
+	int			maxattrs;
+	int			numaliases;
+
+	rel = relation_open(relid, AccessShareLock);
+	maxattrs = RelationGetNumberOfAttributes(rel);
+	numaliases = list_length(eref->colnames);
+
+	for (varattno = 0; varattno < maxattrs; varattno++)
+	{
+		Form_pg_attribute attr = rel->rd_att->attrs[varattno];
+
+		if (attr->attisdropped)
+		{
+			if (include_dropped)
+			{
+				if (colnames)
+					*colnames = lappend(*colnames, makeString(pstrdup("")));
+				if (colvars)
+				{
+					/*
+					 * can't use atttypid here, but it doesn't really matter
+					 * what type the Const claims to be.
+					 */
+					*colvars = lappend(*colvars, makeNullConst(INT4OID));
+				}
+			}
+			continue;
+		}
+
+		if (colnames)
+		{
+			char	   *label;
+
+			if (varattno < numaliases)
+				label = strVal(list_nth(eref->colnames, varattno));
+			else
+				label = NameStr(attr->attname);
+			*colnames = lappend(*colnames, makeString(pstrdup(label)));
+		}
+
+		if (colvars)
+		{
+			Var		   *varnode;
+
+			varnode = makeVar(rtindex, attr->attnum,
+							  attr->atttypid, attr->atttypmod,
+							  sublevels_up);
+
+			*colvars = lappend(*colvars, varnode);
+		}
+	}
+
+	relation_close(rel, AccessShareLock);
+}
+
 /*
  * expandRelAttrs -
  *	  Workhorse for "*" expansion: produce a list of targetentries
  *	  for the attributes of the rte
  */
 List *
-expandRelAttrs(ParseState *pstate, RangeTblEntry *rte)
+expandRelAttrs(ParseState *pstate, List *rtable, int rtindex, int sublevels_up)
 {
 	List	   *names,
 			   *vars;
@@ -1488,9 +1542,9 @@ expandRelAttrs(ParseState *pstate, RangeTblEntry *rte)
 			   *var;
 	List	   *te_list = NIL;
 
-	expandRTE(pstate, rte, &names, &vars);
+	expandRTE(rtable, rtindex, sublevels_up, false, &names, &vars);
 
-	forboth (name, names, var, vars)
+	forboth(name, names, var, vars)
 	{
 		char	   *label = strVal(lfirst(name));
 		Node	   *varnode = (Node *) lfirst(var);
@@ -1698,15 +1752,16 @@ get_rte_attribute_type(RangeTblEntry *rte, AttrNumber attnum,
  *		Check whether attempted attribute ref is to a dropped column
  */
 bool
-get_rte_attribute_is_dropped(RangeTblEntry *rte, AttrNumber attnum)
+get_rte_attribute_is_dropped(List *rtable, int rtindex, AttrNumber attnum)
 {
+	RangeTblEntry *rte = rt_fetch(rtindex, rtable);
 	bool		result;
 
 	switch (rte->rtekind)
 	{
 		case RTE_RELATION:
 			{
-				/* Plain relation RTE --- get the attribute's type info */
+				/* Plain relation RTE --- get the attribute's catalog entry */
 				HeapTuple	tp;
 				Form_pg_attribute att_tup;
 
@@ -1723,9 +1778,37 @@ get_rte_attribute_is_dropped(RangeTblEntry *rte, AttrNumber attnum)
 			}
 			break;
 		case RTE_SUBQUERY:
+			/* Subselect RTEs never have dropped columns */
+			result = false;
+			break;
 		case RTE_JOIN:
-			/* Subselect and join RTEs never have dropped columns */
+			{
+				/*
+				 * A join RTE would not have dropped columns when constructed,
+				 * but one in a stored rule might contain columns that were
+				 * dropped from the underlying tables, if said columns are
+				 * nowhere explicitly referenced in the rule.  So we have to
+				 * recursively look at the referenced column.
+				 */
+				Var		*aliasvar;
+
+				if (attnum <= 0 ||
+					attnum > list_length(rte->joinaliasvars))
+					elog(ERROR, "invalid varattno %d", attnum);
+				aliasvar = (Var *) list_nth(rte->joinaliasvars, attnum - 1);
+				/*
+				 * If the list item isn't a simple Var, then it must
+				 * represent a merged column, ie a USING column, and so it
+				 * couldn't possibly be dropped (since it's referenced in
+				 * the join clause).
+				 */
+				if (!IsA(aliasvar, Var))
 					result = false;
+				else
+					result = get_rte_attribute_is_dropped(rtable,
+														  aliasvar->varno,
+														  aliasvar->varattno);
+			}
 			break;
 		case RTE_FUNCTION:
 			{
@@ -1736,8 +1819,9 @@ get_rte_attribute_is_dropped(RangeTblEntry *rte, AttrNumber attnum)
 				if (OidIsValid(funcrelid))
 				{
 					/*
-					 * Composite data type, i.e. a table's row type Same
-					 * as ordinary relation RTE
+					 * Composite data type, i.e. a table's row type
+					 *
+					 * Same as ordinary relation RTE
 					 */
 					HeapTuple	tp;
 					Form_pg_attribute att_tup;

src/backend/parser/parse_target.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/parse_target.c,v 1.122 2004/06/19 18:19:55 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/parse_target.c,v 1.123 2004/08/19 20:57:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -699,6 +699,8 @@ ExpandColumnRefStar(ParseState *pstate, ColumnRef *cref)
 		char	   *relname;
 		RangeTblEntry *rte;
 		int			sublevels_up;
+		int			rtindex;
+		List	   *rtable;
 
 		switch (numnames)
 		{
@@ -743,7 +745,10 @@ ExpandColumnRefStar(ParseState *pstate, ColumnRef *cref)
 			rte = addImplicitRTE(pstate, makeRangeVar(schemaname,
 													  relname));
 
-		return expandRelAttrs(pstate, rte);
+		rtindex = RTERangeTablePosn(pstate, rte, &sublevels_up);
+		rtable = GetLevelNRangeTable(pstate, sublevels_up);
+
+		return expandRelAttrs(pstate, rtable, rtindex, sublevels_up);
 	}
 }
 
@@ -765,29 +770,31 @@ ExpandAllTables(ParseState *pstate)
 	foreach(ns, pstate->p_namespace)
 	{
 		Node	   *n = (Node *) lfirst(ns);
+		int			rtindex;
 		RangeTblEntry *rte;
 
 		if (IsA(n, RangeTblRef))
-			rte = rt_fetch(((RangeTblRef *) n)->rtindex,
-						   pstate->p_rtable);
+			rtindex = ((RangeTblRef *) n)->rtindex;
 		else if (IsA(n, JoinExpr))
-			rte = rt_fetch(((JoinExpr *) n)->rtindex,
-						   pstate->p_rtable);
+			rtindex = ((JoinExpr *) n)->rtindex;
 		else
 		{
 			elog(ERROR, "unrecognized node type: %d", (int) nodeTag(n));
-			rte = NULL;			/* keep compiler quiet */
+			rtindex = 0;			/* keep compiler quiet */
 		}
 
 		/*
 		 * Ignore added-on relations that were not listed in the FROM
 		 * clause.
 		 */
+		rte = rt_fetch(rtindex, pstate->p_rtable);
 		if (!rte->inFromCl)
 			continue;
 
 		found_table = true;
-		target = list_concat(target, expandRelAttrs(pstate, rte));
+		target = list_concat(target,
+							 expandRelAttrs(pstate, pstate->p_rtable,
+											rtindex, 0));
 	}
 
 	/* Check for SELECT *; */

src/backend/rewrite/rewriteHandler.c

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/rewrite/rewriteHandler.c,v 1.141 2004/08/07 17:40:49 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/rewrite/rewriteHandler.c,v 1.142 2004/08/19 20:57:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -214,8 +214,7 @@ rewriteRuleAction(Query *parsetree,
 		sub_action = (Query *) ResolveNew((Node *) sub_action,
 										  new_varno,
 										  0,
-										  rt_fetch(new_varno,
-												   sub_action->rtable),
+										  sub_action->rtable,
 										  parsetree->targetList,
 										  event,
 										  current_varno);
@@ -1040,7 +1039,7 @@ CopyAndAddInvertedQual(Query *parsetree,
 		new_qual = ResolveNew(new_qual,
 							  PRS2_NEW_VARNO,
 							  0,
-							  rt_fetch(rt_index, parsetree->rtable),
+							  parsetree->rtable,
 							  parsetree->targetList,
 							  event,
 							  rt_index);

src/backend/rewrite/rewriteManip.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/rewrite/rewriteManip.c,v 1.85 2004/08/17 18:47:09 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/rewrite/rewriteManip.c,v 1.86 2004/08/19 20:57:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -18,7 +18,7 @@
 #include "optimizer/clauses.h"
 #include "optimizer/tlist.h"
 #include "parser/parsetree.h"
-#include "parser/parse_clause.h"
+#include "parser/parse_relation.h"
 #include "rewrite/rewriteManip.h"
 #include "utils/lsyscache.h"
 
@@ -853,9 +853,10 @@ AddInvertedQual(Query *parsetree, Node *qual)
  * If not, we either change the unmatched Var's varno to update_varno
  * (when event == CMD_UPDATE) or replace it with a constant NULL.
  *
- * The caller must also provide target_rte, the RTE describing the target
- * relation.  This is needed to handle whole-row Vars referencing the target.
- * We expand such Vars into RowExpr constructs.
+ * The caller must also provide target_rtable, the rangetable containing
+ * the target relation (which must be described by the target_varno'th
+ * RTE in that list).  This is needed to handle whole-row Vars referencing
+ * the target.  We expand such Vars into RowExpr constructs.
  *
  * Note: the business with inserted_sublink is needed to update hasSubLinks
  * in subqueries when the replacement adds a subquery inside a subquery.
@@ -868,7 +869,7 @@ typedef struct
 {
 	int			target_varno;
 	int			sublevels_up;
-	RangeTblEntry *target_rte;
+	List	   *target_rtable;
 	List	   *targetlist;
 	int			event;
 	int			update_varno;
@@ -931,40 +932,21 @@ ResolveNew_mutator(Node *node, ResolveNew_context *context)
 			if (var->varattno == InvalidAttrNumber)
 			{
 				/* Must expand whole-tuple reference into RowExpr */
-				RangeTblEntry *rte = context->target_rte;
 				RowExpr *rowexpr;
-				List	*fields = NIL;
-				AttrNumber nfields = list_length(rte->eref->colnames);
-				AttrNumber nf;
+				List	*fields;
 
-				for (nf = 1; nf <= nfields; nf++)
-				{
-					if (get_rte_attribute_is_dropped(rte, nf))
-					{
 				/*
-						 * can't determine att type here, but it doesn't
-						 * really matter what type the Const claims to be.
-						 */
-						fields = lappend(fields,
-										 makeNullConst(INT4OID));
-					}
-					else
-					{
-						Oid		vartype;
-						int32	vartypmod;
-						Var	   *newvar;
-
-						get_rte_attribute_type(rte, nf, &vartype, &vartypmod);
-						newvar = makeVar(this_varno,
-										 nf,
-										 vartype,
-										 vartypmod,
-										 this_varlevelsup);
-						fields = lappend(fields,
-										 resolve_one_var(newvar, context));
-					}
-				}
-
+				 * If generating an expansion for a var of a named rowtype
+				 * (ie, this is a plain relation RTE), then we must include
+				 * dummy items for dropped columns.  If the var is RECORD
+				 * (ie, this is a JOIN), then omit dropped columns.
+				 */
+				expandRTE(context->target_rtable, this_varno, this_varlevelsup,
+						  (var->vartype != RECORDOID),
+						  NULL, &fields);
+				/* Adjust the generated per-field Vars... */
+				fields = (List *) ResolveNew_mutator((Node *) fields,
+													 context);
 				rowexpr = makeNode(RowExpr);
 				rowexpr->args = fields;
 				rowexpr->row_typeid = var->vartype;
@@ -1003,14 +985,14 @@ ResolveNew_mutator(Node *node, ResolveNew_context *context)
 
 Node *
 ResolveNew(Node *node, int target_varno, int sublevels_up,
-		   RangeTblEntry *target_rte,
+		   List *target_rtable,
 		   List *targetlist, int event, int update_varno)
 {
 	ResolveNew_context context;
 
 	context.target_varno = target_varno;
 	context.sublevels_up = sublevels_up;
-	context.target_rte = target_rte;
+	context.target_rtable = target_rtable;
 	context.targetlist = targetlist;
 	context.event = event;
 	context.update_varno = update_varno;

src/backend/utils/adt/ruleutils.c

@@ -3,7 +3,7 @@
  *				back to source text
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/ruleutils.c,v 1.177 2004/08/17 18:47:09 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/ruleutils.c,v 1.178 2004/08/19 20:57:41 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -203,6 +203,8 @@ static void get_sublink_expr(SubLink *sublink, deparse_context *context);
 static void get_from_clause(Query *query, deparse_context *context);
 static void get_from_clause_item(Node *jtnode, Query *query,
 					 deparse_context *context);
+static void get_from_clause_alias(Alias *alias, int varno,
+								  Query *query, deparse_context *context);
 static void get_from_clause_coldeflist(List *coldeflist,
 						   deparse_context *context);
 static void get_opclass_name(Oid opclass, Oid actual_datatype,
@@ -3962,20 +3964,8 @@ get_from_clause_item(Node *jtnode, Query *query, deparse_context *context)
 			appendStringInfo(buf, " %s",
 							 quote_identifier(rte->alias->aliasname));
 			gavealias = true;
-			if (rte->alias->colnames != NIL && coldeflist == NIL)
-			{
-				ListCell   *col;
-
-				appendStringInfoChar(buf, '(');
-				foreach(col, rte->alias->colnames)
-				{
-					if (col != list_head(rte->alias->colnames))
-						appendStringInfo(buf, ", ");
-					appendStringInfoString(buf,
-										   quote_identifier(strVal(lfirst(col))));
-				}
-				appendStringInfoChar(buf, ')');
-			}
+			if (coldeflist == NIL)
+				get_from_clause_alias(rte->alias, varno, query, context);
 		}
 		else if (rte->rtekind == RTE_RELATION &&
 			 strcmp(rte->eref->aliasname, get_rel_name(rte->relid)) != 0)
@@ -4128,25 +4118,49 @@ get_from_clause_item(Node *jtnode, Query *query, deparse_context *context)
 		{
 			appendStringInfo(buf, " %s",
 							 quote_identifier(j->alias->aliasname));
-			if (j->alias->colnames != NIL)
-			{
+			get_from_clause_alias(j->alias, j->rtindex, query, context);
+		}
+	}
+	else
+		elog(ERROR, "unrecognized node type: %d",
+			 (int) nodeTag(jtnode));
+}
+
+/*
+ * get_from_clause_alias - reproduce column alias list
+ *
+ * This is tricky because we must ignore dropped columns.
+ */
+static void
+get_from_clause_alias(Alias *alias, int varno,
+					  Query *query, deparse_context *context)
+{
+	StringInfo	buf = context->buf;
 	ListCell   *col;
+	AttrNumber attnum;
+	bool		first = true;
 
-				appendStringInfoChar(buf, '(');
-				foreach(col, j->alias->colnames)
+	if (alias == NULL || alias->colnames == NIL)
+		return;					/* definitely nothing to do */
+
+	attnum = 0;
+	foreach(col, alias->colnames)
+	{
+		attnum++;
+		if (get_rte_attribute_is_dropped(query->rtable, varno, attnum))
+			continue;
+		if (first)
 		{
-					if (col != list_head(j->alias->colnames))
+			appendStringInfoChar(buf, '(');
+			first = false;
+		}
+		else
 			appendStringInfo(buf, ", ");
 		appendStringInfoString(buf,
 							   quote_identifier(strVal(lfirst(col))));
 	}
+	if (!first)
 		appendStringInfoChar(buf, ')');
-			}
-		}
-	}
-	else
-		elog(ERROR, "unrecognized node type: %d",
-			 (int) nodeTag(jtnode));
 }
 
 /*

src/include/nodes/parsenodes.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.265 2004/08/04 21:34:24 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.266 2004/08/19 20:57:41 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -447,6 +447,22 @@ typedef struct DefElem
  *	  eref->aliasname is required to be present, and should generally be used
  *	  to identify the RTE for error messages etc.
  *
+ *	  In RELATION RTEs, the colnames in both alias and eref are indexed by
+ *	  physical attribute number; this means there must be colname entries for
+ *	  dropped columns.  When building an RTE we insert empty strings ("") for
+ *	  dropped columns.  Note however that a stored rule may have nonempty
+ *	  colnames for columns dropped since the rule was created (and for that
+ *	  matter the colnames might be out of date due to column renamings).
+ *	  The same comments apply to FUNCTION RTEs when the function's return type
+ *	  is a named composite type.
+ *
+ *	  In JOIN RTEs, the colnames in both alias and eref are one-to-one with
+ *	  joinaliasvars entries.  A JOIN RTE will omit columns of its inputs when
+ *	  those columns are known to be dropped at parse time.  Again, however,
+ *	  a stored rule might contain entries for columns dropped since the rule
+ *	  was created.  (This is only possible for columns not actually referenced
+ *	  in the rule.)
+ *
  *	  inh is TRUE for relation references that should be expanded to include
  *	  inheritance children, if the rel has any.  This *must* be FALSE for
  *	  RTEs other than RTE_RELATION entries.

src/include/nodes/primnodes.h

@@ -10,7 +10,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/primnodes.h,v 1.101 2004/08/17 18:47:09 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/primnodes.h,v 1.102 2004/08/19 20:57:41 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -98,9 +98,9 @@ typedef struct Resdom
  *	  specifies an alias for a range variable; the alias might also
  *	  specify renaming of columns within the table.
  *
- * Note: colnames is a list of Value nodes (always strings).  In an RTE's
- * eref Alias, the colnames list includes dropped columns, so that the
- * colname list position matches the physical attribute number.
+ * Note: colnames is a list of Value nodes (always strings).  In Alias structs
+ * associated with RTEs, there may be entries corresponding to dropped
+ * columns; these are normally empty strings ("").  See parsenodes.h for info.
  */
 typedef struct Alias
 {

src/include/parser/parse_relation.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/parser/parse_relation.h,v 1.44 2004/04/18 18:12:58 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/parser/parse_relation.h,v 1.45 2004/08/19 20:57:41 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -30,6 +30,7 @@ extern int RTERangeTablePosn(ParseState *pstate,
 extern RangeTblEntry *GetRTEByRangeTablePosn(ParseState *pstate,
 											 int varno,
 											 int sublevels_up);
+extern List *GetLevelNRangeTable(ParseState *pstate, int sublevels_up);
 extern Node *scanRTEForColumn(ParseState *pstate, RangeTblEntry *rte,
 							  char *colname);
 extern Node *colNameToVar(ParseState *pstate, char *colname, bool localonly);
@@ -66,9 +67,11 @@ extern RangeTblEntry *addRangeTableEntryForJoin(ParseState *pstate,
 extern void addRTEtoQuery(ParseState *pstate, RangeTblEntry *rte,
 			  bool addToJoinList, bool addToNameSpace);
 extern RangeTblEntry *addImplicitRTE(ParseState *pstate, RangeVar *relation);
-extern void expandRTE(ParseState *pstate, RangeTblEntry *rte,
+extern void expandRTE(List *rtable, int rtindex, int sublevels_up,
+					  bool include_dropped,
 					  List **colnames, List **colvars);
-extern List *expandRelAttrs(ParseState *pstate, RangeTblEntry *rte);
+extern List *expandRelAttrs(ParseState *pstate, List *rtable,
+							int rtindex, int sublevels_up);
 extern int	attnameAttNum(Relation rd, const char *attname, bool sysColOK);
 extern Name attnumAttName(Relation rd, int attid);
 extern Oid	attnumTypeId(Relation rd, int attid);

src/include/parser/parsetree.h

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/parser/parsetree.h,v 1.25 2004/08/17 18:47:09 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/parser/parsetree.h,v 1.26 2004/08/19 20:57:41 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -59,7 +59,7 @@ extern void get_rte_attribute_type(RangeTblEntry *rte, AttrNumber attnum,
  * Check whether an attribute of an RTE has been dropped (note that
  * get_rte_attribute_type will fail on such an attr)
  */
-extern bool get_rte_attribute_is_dropped(RangeTblEntry *rte,
+extern bool get_rte_attribute_is_dropped(List *rtable, int rtindex,
 										 AttrNumber attnum);
 
 

src/include/rewrite/rewriteManip.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/rewrite/rewriteManip.h,v 1.35 2004/05/10 22:44:49 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/rewrite/rewriteManip.h,v 1.36 2004/08/19 20:57:41 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -38,7 +38,7 @@ extern bool checkExprHasAggs(Node *node);
 extern bool checkExprHasSubLink(Node *node);
 
 extern Node *ResolveNew(Node *node, int target_varno, int sublevels_up,
-						RangeTblEntry *target_rte,
+						List *target_rtable,
 						List *targetlist, int event, int update_varno);
 
 #endif   /* REWRITEMANIP_H */