Support data-modifying commands (INSERT/UPDATE/DELETE) in WITH.

This patch implements data-modifying WITH queries according to the
semantics that the updates all happen with the same command counter value,
and in an unspecified order.  Therefore one WITH clause can't see the
effects of another, nor can the outer query see the effects other than
through the RETURNING values.  And attempts to do conflicting updates will
have unpredictable results.  We'll need to document all that.

This commit just fixes the code; documentation updates are waiting on
author.

Marko Tiikkaja and Hitoshi Harada

src/backend/commands/tablecmds.c

@@ -995,7 +995,7 @@ ExecuteTruncate(TruncateStmt *stmt)
 
 	/*
 	 * To fire triggers, we'll need an EState as well as a ResultRelInfo for
-	 * each relation.
+	 * each relation.  We don't need to call ExecOpenIndices, though.
 	 */
 	estate = CreateExecutorState();
 	resultRelInfos = (ResultRelInfo *)
@@ -1008,7 +1008,6 @@ ExecuteTruncate(TruncateStmt *stmt)
 		InitResultRelInfo(resultRelInfo,
 						  rel,
 						  0,	/* dummy rangetable index */
-						  CMD_DELETE,	/* don't need any index info */
 						  0);
 		resultRelInfo++;
 	}

src/backend/commands/view.c

@@ -418,6 +418,20 @@ DefineView(ViewStmt *stmt, const char *queryString)
 		viewParse->commandType != CMD_SELECT)
 		elog(ERROR, "unexpected parse analysis result");
 
+	/*
+	 * Check for unsupported cases.  These tests are redundant with ones in
+	 * DefineQueryRewrite(), but that function will complain about a bogus
+	 * ON SELECT rule, and we'd rather the message complain about a view.
+	 */
+	if (viewParse->intoClause != NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("views must not contain SELECT INTO")));
+	if (viewParse->hasModifyingCTE)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("views must not contain data-modifying statements in WITH")));
+
 	/*
 	 * If a list of column names was given, run through and insert these into
 	 * the actual query tree. - thomas 2000-03-08

src/backend/executor/execUtils.c

@@ -145,6 +145,8 @@ CreateExecutorState(void)
 
 	estate->es_subplanstates = NIL;
 
+	estate->es_auxmodifytables = NIL;
+
 	estate->es_per_tuple_exprcontext = NULL;
 
 	estate->es_epqTuple = NULL;

src/backend/nodes/copyfuncs.c

@@ -80,6 +80,7 @@ _copyPlannedStmt(PlannedStmt *from)
 
 	COPY_SCALAR_FIELD(commandType);
 	COPY_SCALAR_FIELD(hasReturning);
+	COPY_SCALAR_FIELD(hasModifyingCTE);
 	COPY_SCALAR_FIELD(canSetTag);
 	COPY_SCALAR_FIELD(transientPlan);
 	COPY_NODE_FIELD(planTree);
@@ -174,7 +175,9 @@ _copyModifyTable(ModifyTable *from)
 	 * copy remainder of node
 	 */
 	COPY_SCALAR_FIELD(operation);
+	COPY_SCALAR_FIELD(canSetTag);
 	COPY_NODE_FIELD(resultRelations);
+	COPY_SCALAR_FIELD(resultRelIndex);
 	COPY_NODE_FIELD(plans);
 	COPY_NODE_FIELD(returningLists);
 	COPY_NODE_FIELD(rowMarks);
@@ -2384,6 +2387,7 @@ _copyQuery(Query *from)
 	COPY_SCALAR_FIELD(hasSubLinks);
 	COPY_SCALAR_FIELD(hasDistinctOn);
 	COPY_SCALAR_FIELD(hasRecursive);
+	COPY_SCALAR_FIELD(hasModifyingCTE);
 	COPY_SCALAR_FIELD(hasForUpdate);
 	COPY_NODE_FIELD(cteList);
 	COPY_NODE_FIELD(rtable);

src/backend/nodes/equalfuncs.c

@@ -893,6 +893,7 @@ _equalQuery(Query *a, Query *b)
 	COMPARE_SCALAR_FIELD(hasSubLinks);
 	COMPARE_SCALAR_FIELD(hasDistinctOn);
 	COMPARE_SCALAR_FIELD(hasRecursive);
+	COMPARE_SCALAR_FIELD(hasModifyingCTE);
 	COMPARE_SCALAR_FIELD(hasForUpdate);
 	COMPARE_NODE_FIELD(cteList);
 	COMPARE_NODE_FIELD(rtable);

src/backend/nodes/nodeFuncs.c

@@ -2588,6 +2588,56 @@ bool
 					return true;
 			}
 			break;
+		case T_InsertStmt:
+			{
+				InsertStmt *stmt = (InsertStmt *) node;
+
+				if (walker(stmt->relation, context))
+					return true;
+				if (walker(stmt->cols, context))
+					return true;
+				if (walker(stmt->selectStmt, context))
+					return true;
+				if (walker(stmt->returningList, context))
+					return true;
+				if (walker(stmt->withClause, context))
+					return true;
+			}
+			break;
+		case T_DeleteStmt:
+			{
+				DeleteStmt *stmt = (DeleteStmt *) node;
+
+				if (walker(stmt->relation, context))
+					return true;
+				if (walker(stmt->usingClause, context))
+					return true;
+				if (walker(stmt->whereClause, context))
+					return true;
+				if (walker(stmt->returningList, context))
+					return true;
+				if (walker(stmt->withClause, context))
+					return true;
+			}
+			break;
+		case T_UpdateStmt:
+			{
+				UpdateStmt *stmt = (UpdateStmt *) node;
+
+				if (walker(stmt->relation, context))
+					return true;
+				if (walker(stmt->targetList, context))
+					return true;
+				if (walker(stmt->whereClause, context))
+					return true;
+				if (walker(stmt->fromClause, context))
+					return true;
+				if (walker(stmt->returningList, context))
+					return true;
+				if (walker(stmt->withClause, context))
+					return true;
+			}
+			break;
 		case T_SelectStmt:
 			{
 				SelectStmt *stmt = (SelectStmt *) node;

src/backend/nodes/outfuncs.c

@@ -244,6 +244,7 @@ _outPlannedStmt(StringInfo str, PlannedStmt *node)
 
 	WRITE_ENUM_FIELD(commandType, CmdType);
 	WRITE_BOOL_FIELD(hasReturning);
+	WRITE_BOOL_FIELD(hasModifyingCTE);
 	WRITE_BOOL_FIELD(canSetTag);
 	WRITE_BOOL_FIELD(transientPlan);
 	WRITE_NODE_FIELD(planTree);
@@ -328,7 +329,9 @@ _outModifyTable(StringInfo str, ModifyTable *node)
 	_outPlanInfo(str, (Plan *) node);
 
 	WRITE_ENUM_FIELD(operation, CmdType);
+	WRITE_BOOL_FIELD(canSetTag);
 	WRITE_NODE_FIELD(resultRelations);
+	WRITE_INT_FIELD(resultRelIndex);
 	WRITE_NODE_FIELD(plans);
 	WRITE_NODE_FIELD(returningLists);
 	WRITE_NODE_FIELD(rowMarks);
@@ -1639,6 +1642,7 @@ _outPlannerGlobal(StringInfo str, PlannerGlobal *node)
 	WRITE_BITMAPSET_FIELD(rewindPlanIDs);
 	WRITE_NODE_FIELD(finalrtable);
 	WRITE_NODE_FIELD(finalrowmarks);
+	WRITE_NODE_FIELD(resultRelations);
 	WRITE_NODE_FIELD(relationOids);
 	WRITE_NODE_FIELD(invalItems);
 	WRITE_UINT_FIELD(lastPHId);
@@ -1657,7 +1661,6 @@ _outPlannerInfo(StringInfo str, PlannerInfo *node)
 	WRITE_UINT_FIELD(query_level);
 	WRITE_NODE_FIELD(join_rel_list);
 	WRITE_INT_FIELD(join_cur_level);
-	WRITE_NODE_FIELD(resultRelations);
 	WRITE_NODE_FIELD(init_plans);
 	WRITE_NODE_FIELD(cte_plan_ids);
 	WRITE_NODE_FIELD(eq_classes);
@@ -2163,6 +2166,7 @@ _outQuery(StringInfo str, Query *node)
 	WRITE_BOOL_FIELD(hasSubLinks);
 	WRITE_BOOL_FIELD(hasDistinctOn);
 	WRITE_BOOL_FIELD(hasRecursive);
+	WRITE_BOOL_FIELD(hasModifyingCTE);
 	WRITE_BOOL_FIELD(hasForUpdate);
 	WRITE_NODE_FIELD(cteList);
 	WRITE_NODE_FIELD(rtable);

src/backend/nodes/readfuncs.c

@@ -203,6 +203,7 @@ _readQuery(void)
 	READ_BOOL_FIELD(hasSubLinks);
 	READ_BOOL_FIELD(hasDistinctOn);
 	READ_BOOL_FIELD(hasRecursive);
+	READ_BOOL_FIELD(hasModifyingCTE);
 	READ_BOOL_FIELD(hasForUpdate);
 	READ_NODE_FIELD(cteList);
 	READ_NODE_FIELD(rtable);

src/backend/optimizer/plan/createplan.c

@@ -4284,7 +4284,8 @@ make_result(PlannerInfo *root,
  * to make it look better sometime.
  */
 ModifyTable *
-make_modifytable(CmdType operation, List *resultRelations,
+make_modifytable(CmdType operation, bool canSetTag,
+				 List *resultRelations,
 				 List *subplans, List *returningLists,
 				 List *rowMarks, int epqParam)
 {
@@ -4334,7 +4335,9 @@ make_modifytable(CmdType operation, List *resultRelations,
 		node->plan.targetlist = NIL;
 
 	node->operation = operation;
+	node->canSetTag = canSetTag;
 	node->resultRelations = resultRelations;
+	node->resultRelIndex = -1;	/* will be set correctly in setrefs.c */
 	node->plans = subplans;
 	node->returningLists = returningLists;
 	node->rowMarks = rowMarks;

src/backend/optimizer/plan/planner.c

@@ -163,6 +163,7 @@ standard_planner(Query *parse, int cursorOptions, ParamListInfo boundParams)
 	glob->rewindPlanIDs = NULL;
 	glob->finalrtable = NIL;
 	glob->finalrowmarks = NIL;
+	glob->resultRelations = NIL;
 	glob->relationOids = NIL;
 	glob->invalItems = NIL;
 	glob->lastPHId = 0;
@@ -214,6 +215,7 @@ standard_planner(Query *parse, int cursorOptions, ParamListInfo boundParams)
 	/* final cleanup of the plan */
 	Assert(glob->finalrtable == NIL);
 	Assert(glob->finalrowmarks == NIL);
+	Assert(glob->resultRelations == NIL);
 	top_plan = set_plan_references(glob, top_plan,
 								   root->parse->rtable,
 								   root->rowMarks);
@@ -239,11 +241,12 @@ standard_planner(Query *parse, int cursorOptions, ParamListInfo boundParams)
 
 	result->commandType = parse->commandType;
 	result->hasReturning = (parse->returningList != NIL);
+	result->hasModifyingCTE = parse->hasModifyingCTE;
 	result->canSetTag = parse->canSetTag;
 	result->transientPlan = glob->transientPlan;
 	result->planTree = top_plan;
 	result->rtable = glob->finalrtable;
-	result->resultRelations = root->resultRelations;
+	result->resultRelations = glob->resultRelations;
 	result->utilityStmt = parse->utilityStmt;
 	result->intoClause = parse->intoClause;
 	result->subplans = glob->subplans;
@@ -571,7 +574,8 @@ subquery_planner(PlannerGlobal *glob, Query *parse,
 				rowMarks = root->rowMarks;
 
 			plan = (Plan *) make_modifytable(parse->commandType,
-										   copyObject(root->resultRelations),
+											 parse->canSetTag,
+											 list_make1_int(parse->resultRelation),
 											 list_make1(plan),
 											 returningLists,
 											 rowMarks,
@@ -787,7 +791,7 @@ inheritance_planner(PlannerInfo *root)
 		/* Make sure any initplans from this rel get into the outer list */
 		root->init_plans = list_concat(root->init_plans, subroot.init_plans);
 
-		/* Build target-relations list for the executor */
+		/* Build list of target-relation RT indexes */
 		resultRelations = lappend_int(resultRelations, appinfo->child_relid);
 
 		/* Build list of per-relation RETURNING targetlists */
@@ -803,8 +807,6 @@ inheritance_planner(PlannerInfo *root)
 		}
 	}
 
-	root->resultRelations = resultRelations;
-
 	/* Mark result as unordered (probably unnecessary) */
 	root->query_pathkeys = NIL;
 
@@ -814,7 +816,6 @@ inheritance_planner(PlannerInfo *root)
 	 */
 	if (subplans == NIL)
 	{
-		root->resultRelations = list_make1_int(parentRTindex);
 		/* although dummy, it must have a valid tlist for executor */
 		tlist = preprocess_targetlist(root, parse->targetList);
 		return (Plan *) make_result(root,
@@ -849,7 +850,8 @@ inheritance_planner(PlannerInfo *root)
 
 	/* And last, tack on a ModifyTable node to do the UPDATE/DELETE work */
 	return (Plan *) make_modifytable(parse->commandType,
-									 copyObject(root->resultRelations),
+									 parse->canSetTag,
+									 resultRelations,
 									 subplans,
 									 returningLists,
 									 rowMarks,
@@ -1725,12 +1727,6 @@ grouping_planner(PlannerInfo *root, double tuple_fraction)
 										  count_est);
 	}
 
-	/* Compute result-relations list if needed */
-	if (parse->resultRelation)
-		root->resultRelations = list_make1_int(parse->resultRelation);
-	else
-		root->resultRelations = NIL;
-
 	/*
 	 * Return the actual output ordering in query_pathkeys for possible use by
 	 * an outer query level.

src/backend/optimizer/plan/setrefs.c

@@ -173,8 +173,9 @@ static bool extract_query_dependencies_walker(Node *node,
  * The return value is normally the same Plan node passed in, but can be
  * different when the passed-in Plan is a SubqueryScan we decide isn't needed.
  *
- * The flattened rangetable entries are appended to glob->finalrtable,
- * and we also append rowmarks entries to glob->finalrowmarks.
+ * The flattened rangetable entries are appended to glob->finalrtable.
+ * Also, rowmarks entries are appended to glob->finalrowmarks, and the
+ * RT indexes of ModifyTable result relations to glob->resultRelations.
  * Plan dependencies are appended to glob->relationOids (for relations)
  * and glob->invalItems (for everything else).
  *
@@ -552,6 +553,17 @@ set_plan_refs(PlannerGlobal *glob, Plan *plan, int rtoffset)
 											  (Plan *) lfirst(l),
 											  rtoffset);
 				}
+
+				/*
+				 * Append this ModifyTable node's final result relation RT
+				 * index(es) to the global list for the plan, and set its
+				 * resultRelIndex to reflect their starting position in the
+				 * global list.
+				 */
+				splan->resultRelIndex = list_length(glob->resultRelations);
+				glob->resultRelations =
+					list_concat(glob->resultRelations,
+								list_copy(splan->resultRelations));
 			}
 			break;
 		case T_Append:

src/backend/optimizer/plan/subselect.c

@@ -930,6 +930,7 @@ SS_process_ctes(PlannerInfo *root)
 	foreach(lc, root->parse->cteList)
 	{
 		CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
+		CmdType		cmdType = ((Query *) cte->ctequery)->commandType;
 		Query	   *subquery;
 		Plan	   *plan;
 		PlannerInfo *subroot;
@@ -939,9 +940,9 @@ SS_process_ctes(PlannerInfo *root)
 		Param	   *prm;
 
 		/*
-		 * Ignore CTEs that are not actually referenced anywhere.
+		 * Ignore SELECT CTEs that are not actually referenced anywhere.
 		 */
-		if (cte->cterefcount == 0)
+		if (cte->cterefcount == 0 && cmdType == CMD_SELECT)
 		{
 			/* Make a dummy entry in cte_plan_ids */
 			root->cte_plan_ids = lappend_int(root->cte_plan_ids, -1);
@@ -1332,14 +1333,16 @@ simplify_EXISTS_query(Query *query)
 {
 	/*
 	 * We don't try to simplify at all if the query uses set operations,
-	 * aggregates, HAVING, LIMIT/OFFSET, or FOR UPDATE/SHARE; none of these
-	 * seem likely in normal usage and their possible effects are complex.
+	 * aggregates, modifying CTEs, HAVING, LIMIT/OFFSET, or FOR UPDATE/SHARE;
+	 * none of these seem likely in normal usage and their possible effects
+	 * are complex.
 	 */
 	if (query->commandType != CMD_SELECT ||
 		query->intoClause ||
 		query->setOperations ||
 		query->hasAggs ||
 		query->hasWindowFuncs ||
+		query->hasModifyingCTE ||
 		query->havingQual ||
 		query->limitOffset ||
 		query->limitCount ||

src/backend/parser/analyze.c

@@ -288,6 +288,7 @@ transformDeleteStmt(ParseState *pstate, DeleteStmt *stmt)
 	{
 		qry->hasRecursive = stmt->withClause->recursive;
 		qry->cteList = transformWithClause(pstate, stmt->withClause);
+		qry->hasModifyingCTE = pstate->p_hasModifyingCTE;
 	}
 
 	/* set up range table with just the result rel */
@@ -358,6 +359,7 @@ transformInsertStmt(ParseState *pstate, InsertStmt *stmt)
 	{
 		qry->hasRecursive = stmt->withClause->recursive;
 		qry->cteList = transformWithClause(pstate, stmt->withClause);
+		qry->hasModifyingCTE = pstate->p_hasModifyingCTE;
 	}
 
 	/*
@@ -853,6 +855,7 @@ transformSelectStmt(ParseState *pstate, SelectStmt *stmt)
 	{
 		qry->hasRecursive = stmt->withClause->recursive;
 		qry->cteList = transformWithClause(pstate, stmt->withClause);
+		qry->hasModifyingCTE = pstate->p_hasModifyingCTE;
 	}
 
 	/* make FOR UPDATE/FOR SHARE info available to addRangeTableEntry */
@@ -999,6 +1002,7 @@ transformValuesClause(ParseState *pstate, SelectStmt *stmt)
 	{
 		qry->hasRecursive = stmt->withClause->recursive;
 		qry->cteList = transformWithClause(pstate, stmt->withClause);
+		qry->hasModifyingCTE = pstate->p_hasModifyingCTE;
 	}
 
 	/*
@@ -1220,6 +1224,7 @@ transformSetOperationStmt(ParseState *pstate, SelectStmt *stmt)
 	{
 		qry->hasRecursive = stmt->withClause->recursive;
 		qry->cteList = transformWithClause(pstate, stmt->withClause);
+		qry->hasModifyingCTE = pstate->p_hasModifyingCTE;
 	}
 
 	/*
@@ -1816,6 +1821,7 @@ transformUpdateStmt(ParseState *pstate, UpdateStmt *stmt)
 	{
 		qry->hasRecursive = stmt->withClause->recursive;
 		qry->cteList = transformWithClause(pstate, stmt->withClause);
+		qry->hasModifyingCTE = pstate->p_hasModifyingCTE;
 	}
 
 	qry->resultRelation = setTargetTable(pstate, stmt->relation,
@@ -2043,6 +2049,16 @@ transformDeclareCursorStmt(ParseState *pstate, DeclareCursorStmt *stmt)
 				 parser_errposition(pstate,
 								exprLocation((Node *) result->intoClause))));
 
+	/*
+	 * We also disallow data-modifying WITH in a cursor.  (This could be
+	 * allowed, but the semantics of when the updates occur might be
+	 * surprising.)
+	 */
+	if (result->hasModifyingCTE)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("DECLARE CURSOR must not contain data-modifying statements in WITH")));
+
 	/* FOR UPDATE and WITH HOLD are not compatible */
 	if (result->rowMarks != NIL && (stmt->options & CURSOR_OPT_HOLD))
 		ereport(ERROR,

src/backend/parser/gram.y

@@ -8426,12 +8426,12 @@ cte_list:
 		| cte_list ',' common_table_expr		{ $$ = lappend($1, $3); }
 		;
 
-common_table_expr:  name opt_name_list AS select_with_parens
+common_table_expr:  name opt_name_list AS '(' PreparableStmt ')'
 			{
 				CommonTableExpr *n = makeNode(CommonTableExpr);
 				n->ctename = $1;
 				n->aliascolnames = $2;
-				n->ctequery = $4;
+				n->ctequery = $5;
 				n->location = @1;
 				$$ = (Node *) n;
 			}

src/backend/parser/parse_clause.c

@@ -458,7 +458,7 @@ transformCTEReference(ParseState *pstate, RangeVar *r,
 {
 	RangeTblEntry *rte;
 
-	rte = addRangeTableEntryForCTE(pstate, cte, levelsup, r->alias, true);
+	rte = addRangeTableEntryForCTE(pstate, cte, levelsup, r, true);
 
 	return rte;
 }

src/backend/parser/parse_cte.c

@@ -115,7 +115,7 @@ transformWithClause(ParseState *pstate, WithClause *withClause)
 	 * list.  Check this right away so we needn't worry later.
 	 *
 	 * Also, tentatively mark each CTE as non-recursive, and initialize its
-	 * reference count to zero.
+	 * reference count to zero, and set pstate->p_hasModifyingCTE if needed.
 	 */
 	foreach(lc, withClause->ctes)
 	{
@@ -136,6 +136,16 @@ transformWithClause(ParseState *pstate, WithClause *withClause)
 
 		cte->cterecursive = false;
 		cte->cterefcount = 0;
+
+		if (!IsA(cte->ctequery, SelectStmt))
+		{
+			/* must be a data-modifying statement */
+			Assert(IsA(cte->ctequery, InsertStmt) ||
+				   IsA(cte->ctequery, UpdateStmt) ||
+				   IsA(cte->ctequery, DeleteStmt));
+
+			pstate->p_hasModifyingCTE = true;
+		}
 	}
 
 	if (withClause->recursive)
@@ -229,20 +239,20 @@ analyzeCTE(ParseState *pstate, CommonTableExpr *cte)
 	Query	   *query;
 
 	/* Analysis not done already */
-	Assert(IsA(cte->ctequery, SelectStmt));
+	Assert(!IsA(cte->ctequery, Query));
 
 	query = parse_sub_analyze(cte->ctequery, pstate, cte, false);
 	cte->ctequery = (Node *) query;
 
 	/*
-	 * Check that we got something reasonable.	Many of these conditions are
-	 * impossible given restrictions of the grammar, but check 'em anyway.
-	 * (These are the same checks as in transformRangeSubselect.)
+	 * Check that we got something reasonable.  These first two cases should
+	 * be prevented by the grammar.
 	 */
-	if (!IsA(query, Query) ||
-		query->commandType != CMD_SELECT ||
-		query->utilityStmt != NULL)
-		elog(ERROR, "unexpected non-SELECT command in subquery in WITH");
+	if (!IsA(query, Query))
+		elog(ERROR, "unexpected non-Query statement in WITH");
+	if (query->utilityStmt != NULL)
+		elog(ERROR, "unexpected utility statement in WITH");
+
 	if (query->intoClause)
 		ereport(ERROR,
 				(errcode(ERRCODE_SYNTAX_ERROR),
@@ -250,10 +260,28 @@ analyzeCTE(ParseState *pstate, CommonTableExpr *cte)
 				 parser_errposition(pstate,
 								 exprLocation((Node *) query->intoClause))));
 
+	/*
+	 * We disallow data-modifying WITH except at the top level of a query,
+	 * because it's not clear when such a modification should be executed.
+	 */
+	if (query->commandType != CMD_SELECT &&
+		pstate->parentParseState != NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+				 errmsg("WITH clause containing a data-modifying statement must be at the top level"),
+				 parser_errposition(pstate, cte->location)));
+
+	/*
+	 * CTE queries are always marked not canSetTag.  (Currently this only
+	 * matters for data-modifying statements, for which the flag will be
+	 * propagated to the ModifyTable plan node.)
+	 */
+	query->canSetTag = false;
+
 	if (!cte->cterecursive)
 	{
 		/* Compute the output column names/types if not done yet */
-		analyzeCTETargetList(pstate, cte, query->targetList);
+		analyzeCTETargetList(pstate, cte, GetCTETargetList(cte));
 	}
 	else
 	{
@@ -273,7 +301,7 @@ analyzeCTE(ParseState *pstate, CommonTableExpr *cte)
 		lctypmod = list_head(cte->ctecoltypmods);
 		lccoll = list_head(cte->ctecolcollations);
 		varattno = 0;
-		foreach(lctlist, query->targetList)
+		foreach(lctlist, GetCTETargetList(cte))
 		{
 			TargetEntry *te = (TargetEntry *) lfirst(lctlist);
 			Node	   *texpr;
@@ -613,12 +641,20 @@ checkWellFormedRecursion(CteState *cstate)
 		CommonTableExpr *cte = cstate->items[i].cte;
 		SelectStmt *stmt = (SelectStmt *) cte->ctequery;
 
-		Assert(IsA(stmt, SelectStmt));	/* not analyzed yet */
+		Assert(!IsA(stmt, Query));	/* not analyzed yet */
 
 		/* Ignore items that weren't found to be recursive */
 		if (!cte->cterecursive)
 			continue;
 
+		/* Must be a SELECT statement */
+		if (!IsA(stmt, SelectStmt))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_RECURSION),
+					 errmsg("recursive query \"%s\" must not contain data-modifying statements",
+							cte->ctename),
+					 parser_errposition(cstate->pstate, cte->location)));
+
 		/* Must have top-level UNION */
 		if (stmt->op != SETOP_UNION)
 			ereport(ERROR,

src/backend/parser/parse_relation.c

@@ -1363,10 +1363,11 @@ RangeTblEntry *
 addRangeTableEntryForCTE(ParseState *pstate,
 						 CommonTableExpr *cte,
 						 Index levelsup,
-						 Alias *alias,
+						 RangeVar *rv,
 						 bool inFromCl)
 {
 	RangeTblEntry *rte = makeNode(RangeTblEntry);
+	Alias	   *alias = rv->alias;
 	char	   *refname = alias ? alias->aliasname : cte->ctename;
 	Alias	   *eref;
 	int			numaliases;
@@ -1384,6 +1385,24 @@ addRangeTableEntryForCTE(ParseState *pstate,
 	if (!rte->self_reference)
 		cte->cterefcount++;
 
+	/*
+	 * We throw error if the CTE is INSERT/UPDATE/DELETE without RETURNING.
+	 * This won't get checked in case of a self-reference, but that's OK
+	 * because data-modifying CTEs aren't allowed to be recursive anyhow.
+	 */
+	if (IsA(cte->ctequery, Query))
+	{
+		Query  *ctequery = (Query *) cte->ctequery;
+
+		if (ctequery->commandType != CMD_SELECT &&
+			ctequery->returningList == NIL)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("WITH query \"%s\" does not have a RETURNING clause",
+							cte->ctename),
+					 parser_errposition(pstate, rv->location)));
+	}
+
 	rte->ctecoltypes = cte->ctecoltypes;
 	rte->ctecoltypmods = cte->ctecoltypmods;
 	rte->ctecolcollations = cte->ctecolcollations;

src/backend/parser/parse_target.c

@@ -324,10 +324,7 @@ markTargetListOrigin(ParseState *pstate, TargetEntry *tle,
 				CommonTableExpr *cte = GetCTEForRTE(pstate, rte, netlevelsup);
 				TargetEntry *ste;
 
-				/* should be analyzed by now */
-				Assert(IsA(cte->ctequery, Query));
-				ste = get_tle_by_resno(((Query *) cte->ctequery)->targetList,
-									   attnum);
+				ste = get_tle_by_resno(GetCTETargetList(cte), attnum);
 				if (ste == NULL || ste->resjunk)
 					elog(ERROR, "subquery %s does not have attribute %d",
 						 rte->eref->aliasname, attnum);
@@ -1415,10 +1412,7 @@ expandRecordVariable(ParseState *pstate, Var *var, int levelsup)
 				CommonTableExpr *cte = GetCTEForRTE(pstate, rte, netlevelsup);
 				TargetEntry *ste;
 
-				/* should be analyzed by now */
-				Assert(IsA(cte->ctequery, Query));
-				ste = get_tle_by_resno(((Query *) cte->ctequery)->targetList,
-									   attnum);
+				ste = get_tle_by_resno(GetCTETargetList(cte), attnum);
 				if (ste == NULL || ste->resjunk)
 					elog(ERROR, "subquery %s does not have attribute %d",
 						 rte->eref->aliasname, attnum);

src/backend/rewrite/rewriteDefine.c

@@ -329,6 +329,14 @@ DefineQueryRewrite(char *rulename,
 					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 				 errmsg("rules on SELECT must have action INSTEAD SELECT")));
 
+		/*
+		 * ... it cannot contain data-modifying WITH ...
+		 */
+		if (query->hasModifyingCTE)
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("rules on SELECT must not contain data-modifying statements in WITH")));
+
 		/*
 		 * ... there can be no rule qual, ...
 		 */

src/backend/rewrite/rewriteHandler.c

@@ -1801,6 +1801,7 @@ RewriteQuery(Query *parsetree, List *rewrite_events)
 	bool		returning = false;
 	Query	   *qual_product = NULL;
 	List	   *rewritten = NIL;
+	ListCell   *lc1;
 
 	/*
 	 * If the statement is an insert, update, or delete, adjust its targetlist
@@ -1980,6 +1981,67 @@ RewriteQuery(Query *parsetree, List *rewrite_events)
 		heap_close(rt_entry_relation, NoLock);
 	}
 
+	/*
+	 * Recursively process any insert/update/delete statements in WITH clauses
+	 */
+	foreach(lc1, parsetree->cteList)
+	{
+		CommonTableExpr	*cte = (CommonTableExpr *) lfirst(lc1);
+		Query		*ctequery = (Query *) cte->ctequery;
+		List		*newstuff;
+
+		Assert(IsA(ctequery, Query));
+
+		if (ctequery->commandType == CMD_SELECT)
+			continue;
+
+		newstuff = RewriteQuery(ctequery, rewrite_events);
+
+		/*
+		 * Currently we can only handle unconditional, single-statement DO
+		 * INSTEAD rules correctly; we have to get exactly one Query out of
+		 * the rewrite operation to stuff back into the CTE node.
+		 */
+		if (list_length(newstuff) == 1)
+		{
+			/* Push the single Query back into the CTE node */
+			ctequery = (Query *) linitial(newstuff);
+			Assert(IsA(ctequery, Query));
+			/* WITH queries should never be canSetTag */
+			Assert(!ctequery->canSetTag);
+			cte->ctequery = (Node *) ctequery;
+		}
+		else if (newstuff == NIL)
+		{
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("DO INSTEAD NOTHING rules are not supported for data-modifying statements in WITH")));
+		}
+		else
+		{
+			ListCell *lc2;
+
+			/* examine queries to determine which error message to issue */
+			foreach(lc2, newstuff)
+			{
+				Query	*q = (Query *) lfirst(lc2);
+
+				if (q->querySource == QSRC_QUAL_INSTEAD_RULE)
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("conditional DO INSTEAD rules are not supported for data-modifying statements in WITH")));
+				if (q->querySource == QSRC_NON_INSTEAD_RULE)
+					ereport(ERROR,
+							(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+							 errmsg("DO ALSO rules are not supported for data-modifying statements in WITH")));
+			}
+
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("multi-statement DO INSTEAD rules are not supported for data-modifying statements in WITH")));
+		}
+	}
+
 	/*
 	 * For INSERTs, the original query is done first; for UPDATE/DELETE, it is
 	 * done last.  This is needed because update and delete rule actions might
@@ -2033,6 +2095,12 @@ QueryRewrite(Query *parsetree)
 	bool		foundOriginalQuery;
 	Query	   *lastInstead;
 
+	/*
+	 * This function is only applied to top-level original queries
+	 */
+	Assert(parsetree->querySource == QSRC_ORIGINAL);
+	Assert(parsetree->canSetTag);
+
 	/*
 	 * Step 1
 	 *

src/backend/tcop/pquery.c

@@ -143,8 +143,8 @@ FreeQueryDesc(QueryDesc *qdesc)
 
 /*
  * ProcessQuery
- *		Execute a single plannable query within a PORTAL_MULTI_QUERY
- *		or PORTAL_ONE_RETURNING portal
+ *		Execute a single plannable query within a PORTAL_MULTI_QUERY,
+ *		PORTAL_ONE_RETURNING, or PORTAL_ONE_MOD_WITH portal
  *
  *	plan: the plan tree for the query
  *	sourceText: the source text of the query
@@ -263,6 +263,7 @@ ChoosePortalStrategy(List *stmts)
 	 * PORTAL_ONE_SELECT and PORTAL_UTIL_SELECT need only consider the
 	 * single-statement case, since there are no rewrite rules that can add
 	 * auxiliary queries to a SELECT or a utility command.
+	 * PORTAL_ONE_MOD_WITH likewise allows only one top-level statement.
 	 */
 	if (list_length(stmts) == 1)
 	{
@@ -277,7 +278,12 @@ ChoosePortalStrategy(List *stmts)
 				if (query->commandType == CMD_SELECT &&
 					query->utilityStmt == NULL &&
 					query->intoClause == NULL)
-					return PORTAL_ONE_SELECT;
+				{
+					if (query->hasModifyingCTE)
+						return PORTAL_ONE_MOD_WITH;
+					else
+						return PORTAL_ONE_SELECT;
+				}
 				if (query->commandType == CMD_UTILITY &&
 					query->utilityStmt != NULL)
 				{
@@ -297,7 +303,12 @@ ChoosePortalStrategy(List *stmts)
 				if (pstmt->commandType == CMD_SELECT &&
 					pstmt->utilityStmt == NULL &&
 					pstmt->intoClause == NULL)
-					return PORTAL_ONE_SELECT;
+				{
+					if (pstmt->hasModifyingCTE)
+						return PORTAL_ONE_MOD_WITH;
+					else
+						return PORTAL_ONE_SELECT;
+				}
 			}
 		}
 		else
@@ -562,6 +573,7 @@ PortalStart(Portal portal, ParamListInfo params, Snapshot snapshot)
 				break;
 
 			case PORTAL_ONE_RETURNING:
+			case PORTAL_ONE_MOD_WITH:
 
 				/*
 				 * We don't start the executor until we are told to run the
@@ -572,7 +584,6 @@ PortalStart(Portal portal, ParamListInfo params, Snapshot snapshot)
 
 					pstmt = (PlannedStmt *) PortalGetPrimaryStmt(portal);
 					Assert(IsA(pstmt, PlannedStmt));
-					Assert(pstmt->hasReturning);
 					portal->tupDesc =
 						ExecCleanTypeFromTL(pstmt->planTree->targetlist,
 											false);
@@ -780,12 +791,13 @@ PortalRun(Portal portal, long count, bool isTopLevel,
 		{
 			case PORTAL_ONE_SELECT:
 			case PORTAL_ONE_RETURNING:
+			case PORTAL_ONE_MOD_WITH:
 			case PORTAL_UTIL_SELECT:
 
 				/*
 				 * If we have not yet run the command, do so, storing its
-				 * results in the portal's tuplestore. Do this only for the
-				 * PORTAL_ONE_RETURNING and PORTAL_UTIL_SELECT cases.
+				 * results in the portal's tuplestore.  But we don't do that
+				 * for the PORTAL_ONE_SELECT case.
 				 */
 				if (portal->strategy != PORTAL_ONE_SELECT && !portal->holdStore)
 					FillPortalStore(portal, isTopLevel);
@@ -879,8 +891,8 @@ PortalRun(Portal portal, long count, bool isTopLevel,
 /*
  * PortalRunSelect
  *		Execute a portal's query in PORTAL_ONE_SELECT mode, and also
- *		when fetching from a completed holdStore in PORTAL_ONE_RETURNING
- *		and PORTAL_UTIL_SELECT cases.
+ *		when fetching from a completed holdStore in PORTAL_ONE_RETURNING,
+ *		PORTAL_ONE_MOD_WITH, and PORTAL_UTIL_SELECT cases.
  *
  * This handles simple N-rows-forward-or-backward cases.  For more complex
  * nonsequential access to a portal, see PortalRunFetch.
@@ -1031,7 +1043,8 @@ PortalRunSelect(Portal portal,
  * FillPortalStore
  *		Run the query and load result tuples into the portal's tuple store.
  *
- * This is used for PORTAL_ONE_RETURNING and PORTAL_UTIL_SELECT cases only.
+ * This is used for PORTAL_ONE_RETURNING, PORTAL_ONE_MOD_WITH, and
+ * PORTAL_UTIL_SELECT cases only.
  */
 static void
 FillPortalStore(Portal portal, bool isTopLevel)
@@ -1051,6 +1064,7 @@ FillPortalStore(Portal portal, bool isTopLevel)
 	switch (portal->strategy)
 	{
 		case PORTAL_ONE_RETURNING:
+		case PORTAL_ONE_MOD_WITH:
 
 			/*
 			 * Run the portal to completion just as for the default
@@ -1392,6 +1406,7 @@ PortalRunFetch(Portal portal,
 				break;
 
 			case PORTAL_ONE_RETURNING:
+			case PORTAL_ONE_MOD_WITH:
 			case PORTAL_UTIL_SELECT:
 
 				/*
@@ -1455,6 +1470,7 @@ DoPortalRunFetch(Portal portal,
 
 	Assert(portal->strategy == PORTAL_ONE_SELECT ||
 		   portal->strategy == PORTAL_ONE_RETURNING ||
+		   portal->strategy == PORTAL_ONE_MOD_WITH ||
 		   portal->strategy == PORTAL_UTIL_SELECT);
 
 	switch (fdirection)

src/backend/tcop/utility.c

@@ -123,6 +123,8 @@ CommandIsReadOnly(Node *parsetree)
 					return false;		/* SELECT INTO */
 				else if (stmt->rowMarks != NIL)
 					return false;		/* SELECT FOR UPDATE/SHARE */
+				else if (stmt->hasModifyingCTE)
+					return false;		/* data-modifying CTE */
 				else
 					return true;
 			case CMD_UPDATE:

src/backend/utils/adt/ruleutils.c

@@ -4138,7 +4138,7 @@ get_name_for_var_field(Var *var, int fieldno,
 				if (lc != NULL)
 				{
 					Query	   *ctequery = (Query *) cte->ctequery;
-					TargetEntry *ste = get_tle_by_resno(ctequery->targetList,
+					TargetEntry	*ste = get_tle_by_resno(GetCTETargetList(cte),
 														attnum);
 
 					if (ste == NULL || ste->resjunk)

src/backend/utils/cache/plancache.c

@@ -922,6 +922,7 @@ PlanCacheComputeResultDesc(List *stmt_list)
 	switch (ChoosePortalStrategy(stmt_list))
 	{
 		case PORTAL_ONE_SELECT:
+		case PORTAL_ONE_MOD_WITH:
 			node = (Node *) linitial(stmt_list);
 			if (IsA(node, Query))
 			{

src/include/catalog/catversion.h

@@ -53,6 +53,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	201102222
+#define CATALOG_VERSION_NO	201102251
 
 #endif

src/include/executor/executor.h

@@ -163,10 +163,10 @@ extern void ExecutorEnd(QueryDesc *queryDesc);
 extern void standard_ExecutorEnd(QueryDesc *queryDesc);
 extern void ExecutorRewind(QueryDesc *queryDesc);
 extern bool ExecCheckRTPerms(List *rangeTable, bool ereport_on_violation);
+extern void CheckValidResultRel(Relation resultRel, CmdType operation);
 extern void InitResultRelInfo(ResultRelInfo *resultRelInfo,
 				  Relation resultRelationDesc,
 				  Index resultRelationIndex,
-				  CmdType operation,
 				  int instrument_options);
 extern ResultRelInfo *ExecGetTriggerResultRel(EState *estate, Oid relid);
 extern bool ExecContextForcesOids(PlanState *planstate, bool *hasoids);

src/include/nodes/execnodes.h

@@ -346,7 +346,7 @@ typedef struct EState
 	/* If query can insert/delete tuples, the command ID to mark them with */
 	CommandId	es_output_cid;
 
-	/* Info about target table for insert/update/delete queries: */
+	/* Info about target table(s) for insert/update/delete queries: */
 	ResultRelInfo *es_result_relations; /* array of ResultRelInfos */
 	int			es_num_result_relations;		/* length of array */
 	ResultRelInfo *es_result_relation_info;		/* currently active array elt */
@@ -378,6 +378,8 @@ typedef struct EState
 
 	List	   *es_subplanstates;		/* List of PlanState for SubPlans */
 
+	List	   *es_auxmodifytables;	/* List of secondary ModifyTableStates */
+
 	/*
 	 * this ExprContext is for per-output-tuple operations, such as constraint
 	 * checks and index-value computations.  It will be reset for each output
@@ -1041,10 +1043,13 @@ typedef struct ResultState
 typedef struct ModifyTableState
 {
 	PlanState	ps;				/* its first field is NodeTag */
-	CmdType		operation;
+	CmdType		operation;		/* INSERT, UPDATE, or DELETE */
+	bool		canSetTag;		/* do we set the command tag/es_processed? */
+	bool		mt_done;		/* are we done? */
 	PlanState **mt_plans;		/* subplans (one per target rel) */
 	int			mt_nplans;		/* number of plans in the array */
 	int			mt_whichplan;	/* which one is being executed (0..n-1) */
+	ResultRelInfo *resultRelInfo;	/* per-subplan target relations */
 	List	  **mt_arowmarks;	/* per-subplan ExecAuxRowMark lists */
 	EPQState	mt_epqstate;	/* for evaluating EvalPlanQual rechecks */
 	bool		fireBSTriggers; /* do we need to fire stmt triggers? */

src/include/nodes/parsenodes.h

@@ -118,6 +118,7 @@ typedef struct Query
 	bool		hasSubLinks;	/* has subquery SubLink */
 	bool		hasDistinctOn;	/* distinctClause is from DISTINCT ON */
 	bool		hasRecursive;	/* WITH RECURSIVE was specified */
+	bool		hasModifyingCTE;	/* has INSERT/UPDATE/DELETE in WITH */
 	bool		hasForUpdate;	/* FOR UPDATE or FOR SHARE was specified */
 
 	List	   *cteList;		/* WITH list (of CommonTableExpr's) */
@@ -884,7 +885,8 @@ typedef struct CommonTableExpr
 	NodeTag		type;
 	char	   *ctename;		/* query name (never qualified) */
 	List	   *aliascolnames;	/* optional list of column names */
-	Node	   *ctequery;		/* subquery (SelectStmt or Query) */
+	/* SelectStmt/InsertStmt/etc before parse analysis, Query afterwards: */
+	Node	   *ctequery;		/* the CTE's subquery */
 	int			location;		/* token location, or -1 if unknown */
 	/* These fields are set during parse analysis: */
 	bool		cterecursive;	/* is this CTE actually recursive? */
@@ -896,6 +898,14 @@ typedef struct CommonTableExpr
 	List	   *ctecolcollations; /* OID list of column collation OIDs */
 } CommonTableExpr;
 
+/* Convenience macro to get the output tlist of a CTE's query */
+#define GetCTETargetList(cte) \
+	(AssertMacro(IsA((cte)->ctequery, Query)), \
+	 ((Query *) (cte)->ctequery)->commandType == CMD_SELECT ? \
+	 ((Query *) (cte)->ctequery)->targetList : \
+	 ((Query *) (cte)->ctequery)->returningList)
+
+
 /*****************************************************************************
  *		Optimizable Statements
  *****************************************************************************/

src/include/nodes/plannodes.h

@@ -40,6 +40,8 @@ typedef struct PlannedStmt
 
 	bool		hasReturning;	/* is it insert|update|delete RETURNING? */
 
+	bool		hasModifyingCTE;	/* has insert|update|delete in WITH? */
+
 	bool		canSetTag;		/* do I set the command result tag? */
 
 	bool		transientPlan;	/* redo plan when TransactionXmin changes? */
@@ -167,7 +169,9 @@ typedef struct ModifyTable
 {
 	Plan		plan;
 	CmdType		operation;		/* INSERT, UPDATE, or DELETE */
+	bool		canSetTag;		/* do we set the command tag/es_processed? */
 	List	   *resultRelations;	/* integer list of RT indexes */
+	int			resultRelIndex;	/* index of first resultRel in plan's list */
 	List	   *plans;			/* plan(s) producing source data */
 	List	   *returningLists; /* per-target-table RETURNING tlists */
 	List	   *rowMarks;		/* PlanRowMarks (non-locking only) */

src/include/nodes/relation.h

@@ -76,6 +76,8 @@ typedef struct PlannerGlobal
 
 	List	   *finalrowmarks;	/* "flat" list of PlanRowMarks */
 
+	List	   *resultRelations;	/* "flat" list of integer RT indexes */
+
 	List	   *relationOids;	/* OIDs of relations the plan depends on */
 
 	List	   *invalItems;		/* other dependencies, as PlanInvalItems */
@@ -154,8 +156,6 @@ typedef struct PlannerInfo
 	List	  **join_rel_level; /* lists of join-relation RelOptInfos */
 	int			join_cur_level; /* index of list being extended */
 
-	List	   *resultRelations;	/* integer list of RT indexes, or NIL */
-
 	List	   *init_plans;		/* init SubPlans for query */
 
 	List	   *cte_plan_ids;	/* per-CTE-item list of subplan IDs */

src/include/optimizer/planmain.h

@@ -78,8 +78,8 @@ extern SetOp *make_setop(SetOpCmd cmd, SetOpStrategy strategy, Plan *lefttree,
 		   long numGroups, double outputRows);
 extern Result *make_result(PlannerInfo *root, List *tlist,
 			Node *resconstantqual, Plan *subplan);
-extern ModifyTable *make_modifytable(CmdType operation, List *resultRelations,
-				 List *subplans, List *returningLists,
+extern ModifyTable *make_modifytable(CmdType operation, bool canSetTag,
+				 List *resultRelations, List *subplans, List *returningLists,
 				 List *rowMarks, int epqParam);
 extern bool is_projection_capable_plan(Plan *plan);
 

src/include/parser/parse_node.h

@@ -103,6 +103,7 @@ struct ParseState
 	bool		p_hasAggs;
 	bool		p_hasWindowFuncs;
 	bool		p_hasSubLinks;
+	bool		p_hasModifyingCTE;
 	bool		p_is_insert;
 	bool		p_is_update;
 	bool		p_locked_from_parent;

src/include/parser/parse_relation.h

@@ -74,7 +74,7 @@ extern RangeTblEntry *addRangeTableEntryForJoin(ParseState *pstate,
 extern RangeTblEntry *addRangeTableEntryForCTE(ParseState *pstate,
 						 CommonTableExpr *cte,
 						 Index levelsup,
-						 Alias *alias,
+						 RangeVar *rv,
 						 bool inFromCl);
 extern bool isLockedRefname(ParseState *pstate, const char *refname);
 extern void addRTEtoQuery(ParseState *pstate, RangeTblEntry *rte,

src/include/utils/portal.h

@@ -71,6 +71,11 @@
  * can't cope, and also because we don't want to risk failing to execute
  * all the auxiliary queries.)
  *
+ * PORTAL_ONE_MOD_WITH: the portal contains one single SELECT query, but
+ * it has data-modifying CTEs.  This is currently treated the same as the
+ * PORTAL_ONE_RETURNING case because of the possibility of needing to fire
+ * triggers.  It may act more like PORTAL_ONE_SELECT in future.
+ *
  * PORTAL_UTIL_SELECT: the portal contains a utility statement that returns
  * a SELECT-like result (for example, EXPLAIN or SHOW).  On first execution,
  * we run the statement and dump its results into the portal tuplestore;
@@ -83,6 +88,7 @@ typedef enum PortalStrategy
 {
 	PORTAL_ONE_SELECT,
 	PORTAL_ONE_RETURNING,
+	PORTAL_ONE_MOD_WITH,
 	PORTAL_UTIL_SELECT,
 	PORTAL_MULTI_QUERY
 } PortalStrategy;

src/test/regress/expected/with.out

@@ -738,7 +738,7 @@ WITH RECURSIVE
 (54 rows)
 
 --
--- Test WITH attached to a DML statement
+-- Test WITH attached to a data-modifying statement
 --
 CREATE TEMPORARY TABLE y (a INTEGER);
 INSERT INTO y SELECT generate_series(1, 10);
@@ -1159,3 +1159,564 @@ SELECT * FROM t;
  10
 (55 rows)
 
+--
+-- Data-modifying statements in WITH
+--
+-- INSERT ... RETURNING
+WITH t AS (
+    INSERT INTO y
+    VALUES
+        (11),
+        (12),
+        (13),
+        (14),
+        (15),
+        (16),
+        (17),
+        (18),
+        (19),
+        (20)
+    RETURNING *
+)
+SELECT * FROM t;
+ a  
+----
+ 11
+ 12
+ 13
+ 14
+ 15
+ 16
+ 17
+ 18
+ 19
+ 20
+(10 rows)
+
+SELECT * FROM y;
+ a  
+----
+  1
+  2
+  3
+  4
+  5
+  6
+  7
+  8
+  9
+ 10
+ 11
+ 12
+ 13
+ 14
+ 15
+ 16
+ 17
+ 18
+ 19
+ 20
+(20 rows)
+
+-- UPDATE ... RETURNING
+WITH t AS (
+    UPDATE y
+    SET a=a+1
+    RETURNING *
+)
+SELECT * FROM t;
+ a  
+----
+  2
+  3
+  4
+  5
+  6
+  7
+  8
+  9
+ 10
+ 11
+ 12
+ 13
+ 14
+ 15
+ 16
+ 17
+ 18
+ 19
+ 20
+ 21
+(20 rows)
+
+SELECT * FROM y;
+ a  
+----
+  2
+  3
+  4
+  5
+  6
+  7
+  8
+  9
+ 10
+ 11
+ 12
+ 13
+ 14
+ 15
+ 16
+ 17
+ 18
+ 19
+ 20
+ 21
+(20 rows)
+
+-- DELETE ... RETURNING
+WITH t AS (
+    DELETE FROM y
+    WHERE a <= 10
+    RETURNING *
+)
+SELECT * FROM t;
+ a  
+----
+  2
+  3
+  4
+  5
+  6
+  7
+  8
+  9
+ 10
+(9 rows)
+
+SELECT * FROM y;
+ a  
+----
+ 11
+ 12
+ 13
+ 14
+ 15
+ 16
+ 17
+ 18
+ 19
+ 20
+ 21
+(11 rows)
+
+-- forward reference
+WITH RECURSIVE t AS (
+	INSERT INTO y
+		SELECT a+5 FROM t2 WHERE a > 5
+	RETURNING *
+), t2 AS (
+	UPDATE y SET a=a-11 RETURNING *
+)
+SELECT * FROM t
+UNION ALL
+SELECT * FROM t2;
+ a  
+----
+ 11
+ 12
+ 13
+ 14
+ 15
+  0
+  1
+  2
+  3
+  4
+  5
+  6
+  7
+  8
+  9
+ 10
+(16 rows)
+
+SELECT * FROM y;
+ a  
+----
+  0
+  1
+  2
+  3
+  4
+  5
+  6
+ 11
+  7
+ 12
+  8
+ 13
+  9
+ 14
+ 10
+ 15
+(16 rows)
+
+-- unconditional DO INSTEAD rule
+CREATE RULE y_rule AS ON DELETE TO y DO INSTEAD
+  INSERT INTO y VALUES(42) RETURNING *;
+WITH t AS (
+	DELETE FROM y RETURNING *
+)
+SELECT * FROM t;
+ a  
+----
+ 42
+(1 row)
+
+SELECT * FROM y;
+ a  
+----
+  0
+  1
+  2
+  3
+  4
+  5
+  6
+ 11
+  7
+ 12
+  8
+ 13
+  9
+ 14
+ 10
+ 15
+ 42
+(17 rows)
+
+DROP RULE y_rule ON y;
+-- a truly recursive CTE in the same list
+WITH RECURSIVE t(a) AS (
+	SELECT 0
+		UNION ALL
+	SELECT a+1 FROM t WHERE a+1 < 5
+), t2 as (
+	INSERT INTO y
+		SELECT * FROM t RETURNING *
+)
+SELECT * FROM t2 JOIN y USING (a) ORDER BY a;
+ a 
+---
+ 0
+ 1
+ 2
+ 3
+ 4
+(5 rows)
+
+SELECT * FROM y;
+ a  
+----
+  0
+  1
+  2
+  3
+  4
+  5
+  6
+ 11
+  7
+ 12
+  8
+ 13
+  9
+ 14
+ 10
+ 15
+ 42
+  0
+  1
+  2
+  3
+  4
+(22 rows)
+
+-- data-modifying WITH in a modifying statement
+WITH t AS (
+    DELETE FROM y
+    WHERE a <= 10
+    RETURNING *
+)
+INSERT INTO y SELECT -a FROM t RETURNING *;
+  a  
+-----
+   0
+  -1
+  -2
+  -3
+  -4
+  -5
+  -6
+  -7
+  -8
+  -9
+ -10
+   0
+  -1
+  -2
+  -3
+  -4
+(16 rows)
+
+SELECT * FROM y;
+  a  
+-----
+  11
+  12
+  13
+  14
+  15
+  42
+   0
+  -1
+  -2
+  -3
+  -4
+  -5
+  -6
+  -7
+  -8
+  -9
+ -10
+   0
+  -1
+  -2
+  -3
+  -4
+(22 rows)
+
+-- check that WITH query is run to completion even if outer query isn't
+WITH t AS (
+    UPDATE y SET a = a * 100 RETURNING *
+)
+SELECT * FROM t LIMIT 10;
+  a   
+------
+ 1100
+ 1200
+ 1300
+ 1400
+ 1500
+ 4200
+    0
+ -100
+ -200
+ -300
+(10 rows)
+
+SELECT * FROM y;
+   a   
+-------
+  1100
+  1200
+  1300
+  1400
+  1500
+  4200
+     0
+  -100
+  -200
+  -300
+  -400
+  -500
+  -600
+  -700
+  -800
+  -900
+ -1000
+     0
+  -100
+  -200
+  -300
+  -400
+(22 rows)
+
+-- triggers
+TRUNCATE TABLE y;
+INSERT INTO y SELECT generate_series(1, 10);
+CREATE FUNCTION y_trigger() RETURNS trigger AS $$
+begin
+  raise notice 'y_trigger: a = %', new.a;
+  return new;
+end;
+$$ LANGUAGE plpgsql;
+CREATE TRIGGER y_trig BEFORE INSERT ON y FOR EACH ROW
+    EXECUTE PROCEDURE y_trigger();
+WITH t AS (
+    INSERT INTO y
+    VALUES
+        (21),
+        (22),
+        (23)
+    RETURNING *
+)
+SELECT * FROM t;
+NOTICE:  y_trigger: a = 21
+NOTICE:  y_trigger: a = 22
+NOTICE:  y_trigger: a = 23
+ a  
+----
+ 21
+ 22
+ 23
+(3 rows)
+
+SELECT * FROM y;
+ a  
+----
+  1
+  2
+  3
+  4
+  5
+  6
+  7
+  8
+  9
+ 10
+ 21
+ 22
+ 23
+(13 rows)
+
+DROP TRIGGER y_trig ON y;
+CREATE TRIGGER y_trig AFTER INSERT ON y FOR EACH ROW
+    EXECUTE PROCEDURE y_trigger();
+WITH t AS (
+    INSERT INTO y
+    VALUES
+        (31),
+        (32),
+        (33)
+    RETURNING *
+)
+SELECT * FROM t;
+NOTICE:  y_trigger: a = 31
+NOTICE:  y_trigger: a = 32
+NOTICE:  y_trigger: a = 33
+ a  
+----
+ 31
+ 32
+ 33
+(3 rows)
+
+SELECT * FROM y;
+ a  
+----
+  1
+  2
+  3
+  4
+  5
+  6
+  7
+  8
+  9
+ 10
+ 21
+ 22
+ 23
+ 31
+ 32
+ 33
+(16 rows)
+
+DROP TRIGGER y_trig ON y;
+CREATE OR REPLACE FUNCTION y_trigger() RETURNS trigger AS $$
+begin
+  raise notice 'y_trigger';
+  return null;
+end;
+$$ LANGUAGE plpgsql;
+CREATE TRIGGER y_trig AFTER INSERT ON y FOR EACH STATEMENT
+    EXECUTE PROCEDURE y_trigger();
+WITH t AS (
+    INSERT INTO y
+    VALUES
+        (41),
+        (42),
+        (43)
+    RETURNING *
+)
+SELECT * FROM t;
+NOTICE:  y_trigger
+ a  
+----
+ 41
+ 42
+ 43
+(3 rows)
+
+SELECT * FROM y;
+ a  
+----
+  1
+  2
+  3
+  4
+  5
+  6
+  7
+  8
+  9
+ 10
+ 21
+ 22
+ 23
+ 31
+ 32
+ 33
+ 41
+ 42
+ 43
+(19 rows)
+
+DROP TRIGGER y_trig ON y;
+DROP FUNCTION y_trigger();
+-- error cases
+-- data-modifying WITH tries to use its own output
+WITH RECURSIVE t AS (
+	INSERT INTO y
+		SELECT * FROM t
+)
+VALUES(FALSE);
+ERROR:  recursive query "t" must not contain data-modifying statements
+LINE 1: WITH RECURSIVE t AS (
+                       ^
+-- no RETURNING in a referenced data-modifying WITH
+WITH t AS (
+	INSERT INTO y VALUES(0)
+)
+SELECT * FROM t;
+ERROR:  WITH query "t" does not have a RETURNING clause
+LINE 4: SELECT * FROM t;
+                      ^
+-- data-modifying WITH allowed only at the top level
+SELECT * FROM (
+	WITH t AS (UPDATE y SET a=a+1 RETURNING *)
+	SELECT * FROM t
+) ss;
+ERROR:  WITH clause containing a data-modifying statement must be at the top level
+LINE 2:  WITH t AS (UPDATE y SET a=a+1 RETURNING *)
+              ^
+-- most variants of rules aren't allowed
+CREATE RULE y_rule AS ON INSERT TO y WHERE a=0 DO INSTEAD DELETE FROM y;
+WITH t AS (
+	INSERT INTO y VALUES(0)
+)
+VALUES(FALSE);
+ERROR:  conditional DO INSTEAD rules are not supported for data-modifying statements in WITH
+DROP RULE y_rule ON y;

src/test/regress/sql/with.sql

@@ -339,7 +339,7 @@ WITH RECURSIVE
  SELECT * FROM z;
 
 --
--- Test WITH attached to a DML statement
+-- Test WITH attached to a data-modifying statement
 --
 
 CREATE TEMPORARY TABLE y (a INTEGER);
@@ -538,3 +538,205 @@ WITH RECURSIVE t(j) AS (
     SELECT j+1 FROM t WHERE j < 10
 )
 SELECT * FROM t;
+
+--
+-- Data-modifying statements in WITH
+--
+
+-- INSERT ... RETURNING
+WITH t AS (
+    INSERT INTO y
+    VALUES
+        (11),
+        (12),
+        (13),
+        (14),
+        (15),
+        (16),
+        (17),
+        (18),
+        (19),
+        (20)
+    RETURNING *
+)
+SELECT * FROM t;
+
+SELECT * FROM y;
+
+-- UPDATE ... RETURNING
+WITH t AS (
+    UPDATE y
+    SET a=a+1
+    RETURNING *
+)
+SELECT * FROM t;
+
+SELECT * FROM y;
+
+-- DELETE ... RETURNING
+WITH t AS (
+    DELETE FROM y
+    WHERE a <= 10
+    RETURNING *
+)
+SELECT * FROM t;
+
+SELECT * FROM y;
+
+-- forward reference
+WITH RECURSIVE t AS (
+	INSERT INTO y
+		SELECT a+5 FROM t2 WHERE a > 5
+	RETURNING *
+), t2 AS (
+	UPDATE y SET a=a-11 RETURNING *
+)
+SELECT * FROM t
+UNION ALL
+SELECT * FROM t2;
+
+SELECT * FROM y;
+
+-- unconditional DO INSTEAD rule
+CREATE RULE y_rule AS ON DELETE TO y DO INSTEAD
+  INSERT INTO y VALUES(42) RETURNING *;
+
+WITH t AS (
+	DELETE FROM y RETURNING *
+)
+SELECT * FROM t;
+
+SELECT * FROM y;
+
+DROP RULE y_rule ON y;
+
+-- a truly recursive CTE in the same list
+WITH RECURSIVE t(a) AS (
+	SELECT 0
+		UNION ALL
+	SELECT a+1 FROM t WHERE a+1 < 5
+), t2 as (
+	INSERT INTO y
+		SELECT * FROM t RETURNING *
+)
+SELECT * FROM t2 JOIN y USING (a) ORDER BY a;
+
+SELECT * FROM y;
+
+-- data-modifying WITH in a modifying statement
+WITH t AS (
+    DELETE FROM y
+    WHERE a <= 10
+    RETURNING *
+)
+INSERT INTO y SELECT -a FROM t RETURNING *;
+
+SELECT * FROM y;
+
+-- check that WITH query is run to completion even if outer query isn't
+WITH t AS (
+    UPDATE y SET a = a * 100 RETURNING *
+)
+SELECT * FROM t LIMIT 10;
+
+SELECT * FROM y;
+
+-- triggers
+
+TRUNCATE TABLE y;
+INSERT INTO y SELECT generate_series(1, 10);
+
+CREATE FUNCTION y_trigger() RETURNS trigger AS $$
+begin
+  raise notice 'y_trigger: a = %', new.a;
+  return new;
+end;
+$$ LANGUAGE plpgsql;
+
+CREATE TRIGGER y_trig BEFORE INSERT ON y FOR EACH ROW
+    EXECUTE PROCEDURE y_trigger();
+
+WITH t AS (
+    INSERT INTO y
+    VALUES
+        (21),
+        (22),
+        (23)
+    RETURNING *
+)
+SELECT * FROM t;
+
+SELECT * FROM y;
+
+DROP TRIGGER y_trig ON y;
+
+CREATE TRIGGER y_trig AFTER INSERT ON y FOR EACH ROW
+    EXECUTE PROCEDURE y_trigger();
+
+WITH t AS (
+    INSERT INTO y
+    VALUES
+        (31),
+        (32),
+        (33)
+    RETURNING *
+)
+SELECT * FROM t;
+
+SELECT * FROM y;
+
+DROP TRIGGER y_trig ON y;
+
+CREATE OR REPLACE FUNCTION y_trigger() RETURNS trigger AS $$
+begin
+  raise notice 'y_trigger';
+  return null;
+end;
+$$ LANGUAGE plpgsql;
+
+CREATE TRIGGER y_trig AFTER INSERT ON y FOR EACH STATEMENT
+    EXECUTE PROCEDURE y_trigger();
+
+WITH t AS (
+    INSERT INTO y
+    VALUES
+        (41),
+        (42),
+        (43)
+    RETURNING *
+)
+SELECT * FROM t;
+
+SELECT * FROM y;
+
+DROP TRIGGER y_trig ON y;
+DROP FUNCTION y_trigger();
+
+-- error cases
+
+-- data-modifying WITH tries to use its own output
+WITH RECURSIVE t AS (
+	INSERT INTO y
+		SELECT * FROM t
+)
+VALUES(FALSE);
+
+-- no RETURNING in a referenced data-modifying WITH
+WITH t AS (
+	INSERT INTO y VALUES(0)
+)
+SELECT * FROM t;
+
+-- data-modifying WITH allowed only at the top level
+SELECT * FROM (
+	WITH t AS (UPDATE y SET a=a+1 RETURNING *)
+	SELECT * FROM t
+) ss;
+
+-- most variants of rules aren't allowed
+CREATE RULE y_rule AS ON INSERT TO y WHERE a=0 DO INSTEAD DELETE FROM y;
+WITH t AS (
+	INSERT INTO y VALUES(0)
+)
+VALUES(FALSE);
+DROP RULE y_rule ON y;