Initial changes

src/backend/distributed/planner/merge_planner.c

@@ -857,8 +857,11 @@ ConvertRelationRTEIntoSubquery(Query *mergeQuery, RangeTblEntry *sourceRte,
 	/* set the FROM expression to the subquery */
 	newRangeTableRef->rtindex = SINGLE_RTE_INDEX;
 	sourceResultsQuery->jointree = makeFromExpr(list_make1(newRangeTableRef), NULL);
+
+	bool isMergeQuery = true;
 	sourceResultsQuery->targetList =
-		CreateAllTargetListForRelation(sourceRte->relid, requiredAttributes);
+		CreateAllTargetListForRelation(sourceRte->relid, requiredAttributes,
+									   isMergeQuery);
 	List *restrictionList =
 		GetRestrictInfoListForRelation(sourceRte, plannerRestrictionContext);
 	List *copyRestrictionList = copyObject(restrictionList);

src/backend/distributed/planner/query_colocation_checker.c

@@ -325,13 +325,14 @@ WrapRteRelationIntoSubquery(RangeTblEntry *rteRelation,
  * as a NULL column.
  */
 List *
-CreateAllTargetListForRelation(Oid relationId, List *requiredAttributes)
+CreateAllTargetListForRelation(Oid relationId, List *requiredAttributes, bool
+							   isMergeQuery)
 {
 	Relation relation = relation_open(relationId, AccessShareLock);
 	int numberOfAttributes = RelationGetNumberOfAttributes(relation);
 
 	List *targetList = NIL;
-	int varAttrNo = 1;
+	int colAppendIdx = 1;
 
 	for (int attrNum = 1; attrNum <= numberOfAttributes; attrNum++)
 	{
@@ -361,8 +362,9 @@ CreateAllTargetListForRelation(Oid relationId, List *requiredAttributes)
 		}
 		else
 		{
+			int varAttNum = isMergeQuery ? attrNum : colAppendIdx++;
 			TargetEntry *targetEntry =
-				CreateTargetEntryForColumn(attributeTuple, SINGLE_RTE_INDEX, varAttrNo++,
+				CreateTargetEntryForColumn(attributeTuple, SINGLE_RTE_INDEX, varAttNum,
 										   resNo);
 			targetList = lappend(targetList, targetEntry);
 		}

src/backend/distributed/planner/recursive_planning.c

@@ -1767,8 +1767,11 @@ ReplaceRTERelationWithRteSubquery(RangeTblEntry *rangeTableEntry,
 {
 	Query *subquery = WrapRteRelationIntoSubquery(rangeTableEntry, requiredAttrNumbers,
 												  perminfo);
+
+	bool isMergeQuery = false;
 	List *outerQueryTargetList = CreateAllTargetListForRelation(rangeTableEntry->relid,
-																requiredAttrNumbers);
+																requiredAttrNumbers,
+																isMergeQuery);
 
 	List *restrictionList =
 		GetRestrictInfoListForRelation(rangeTableEntry,
@@ -2109,7 +2112,6 @@ TransformFunctionRTE(RangeTblEntry *rangeTblEntry)
 			subquery->targetList = lappend(subquery->targetList, targetEntry);
 		}
 	}
-
 	/*
 	 * If tupleDesc is NULL we have 2 different cases:
 	 *
@@ -2159,7 +2161,6 @@ TransformFunctionRTE(RangeTblEntry *rangeTblEntry)
 				columnType = list_nth_oid(rangeTblFunction->funccoltypes,
 										  targetColumnIndex);
 			}
-
 			/* use the types in the function definition otherwise */
 			else
 			{

src/include/distributed/query_colocation_checker.h

@@ -38,6 +38,7 @@ extern bool SubqueryColocated(Query *subquery, ColocatedJoinChecker *context);
 extern Query * WrapRteRelationIntoSubquery(RangeTblEntry *rteRelation,
 										   List *requiredAttributes,
 										   RTEPermissionInfo *perminfo);
-extern List * CreateAllTargetListForRelation(Oid relationId, List *requiredAttributes);
+extern List * CreateAllTargetListForRelation(Oid relationId, List *requiredAttributes,
+											 bool isMergeQuery);
 
 #endif /* QUERY_COLOCATION_CHECKER_H */

src/test/regress/sql/merge_vcore.sql

@@ -312,6 +312,63 @@ WHEN MATCHED THEN DO NOTHING;
 DROP TABLE IF EXISTS source;
 DROP TABLE IF EXISTS target;
 
+
+-- Bug Fix Test as part of this PR
+-- Test 1
+CREATE TABLE source (
+    id int,
+    age int,
+    salary int
+);
+
+CREATE TABLE target (
+    id int,
+    age int,
+    salary int
+);
+
+SELECT create_distributed_table('source', 'id', colocate_with=>'none');
+SELECT create_distributed_table('target', 'id', colocate_with=>'none');
+
+INSERT INTO source (id, age, salary) VALUES  (1,30, 100000);
+
+MERGE INTO ONLY target USING source ON (source.id = target.id)
+WHEN NOT MATCHED THEN
+INSERT (id, salary) VALUES (source.id, source.salary);
+
+SELECT * FROM TARGET;
+DROP TABLE IF EXISTS source;
+DROP TABLE IF EXISTS target;
+
+
+-- Test 2
+CREATE TABLE source (
+    id int,
+    age int,
+    salary int
+);
+
+CREATE TABLE target (
+    id int,
+    age int,
+    salary int
+);
+
+SELECT create_distributed_table('source', 'id', colocate_with=>'none');
+SELECT create_distributed_table('target', 'id', colocate_with=>'none');
+
+INSERT INTO source (id, age, salary) VALUES  (1,30, 100000);
+
+MERGE INTO ONLY target USING source ON (source.id = target.id)
+WHEN NOT MATCHED THEN
+INSERT (salary, id) VALUES (source.salary, source.id);
+
+SELECT * FROM TARGET;
+DROP TABLE IF EXISTS source;
+DROP TABLE IF EXISTS target;
+
+
+
 DROP SCHEMA IF EXISTS merge_vcore_schema CASCADE;