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

5 files changed, 61 insertions, 1 deletions

diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index 04763d44eb..7a1bc1562f 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/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);
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index c896f49ff6..d43c51e275 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/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);
diff --git a/src/backend/nodes/nodeFuncs.c b/src/backend/nodes/nodeFuncs.c
index d4b9242917..c3c5d8e6e5 100644
--- a/src/backend/nodes/nodeFuncs.c
+++ b/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;
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index 706b2425cf..4aae2b33a6 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/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);
diff --git a/src/backend/nodes/readfuncs.c b/src/backend/nodes/readfuncs.c
index c76884e991..09c5e25012 100644
--- a/src/backend/nodes/readfuncs.c
+++ b/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);