fix expalin merge into and fastcheck test case

src/common/backend/utils/adt/ruleutils.cpp

@@ -4275,7 +4275,12 @@ static void set_deparse_planstate(deparse_namespace* dpns, PlanState* ps)
     } else
         dpns->inner_planstate = innerPlanState(ps);
 
+#ifdef ENABLE_MULTIPLE_NODES
     if (IsA(ps, ModifyTableState))
+#else
+    if (IsA(ps, ModifyTableState) && ((ModifyTableState*)ps)->mt_upsert != NULL &&
+        ((ModifyTableState*)ps)->mt_upsert->us_action != UPSERT_NONE)
+#endif
         dpns->inner_tlist = ((ModifyTableState*)ps)->mt_upsert->us_excludedtlist;
     else if (dpns->inner_planstate != NULL)
         dpns->inner_tlist = dpns->inner_planstate->plan->targetlist;

src/test/regress/expected/merge_1.out

@@ -51,6 +51,27 @@ INSERT INTO newproducts_row SELECT * FROM newproducts_base;
 ANALYZE products_row;
 ANALYZE newproducts_row;
 -- explain verbose
+EXPLAIN (VERBOSE on, COSTS off)
+MERGE INTO products_row p
+USING newproducts_row np
+ON p.product_id = np.product_id
+WHEN MATCHED THEN
+  UPDATE SET product_name = np.product_name, category = np.category, total = np.total where np.product_id = 5;
+                                                                QUERY PLAN                                                                 
+-------------------------------------------------------------------------------------------------------------------------------------------
+ Merge on mergeinto_1.products_row p
+   Update Cond: (p.product_id = 5)
+   ->  Hash Join
+         Output: np.product_id, np.product_name, np.category, np.total, p.product_id, p.product_name, p.category, p.total, p.ctid, np.ctid
+         Hash Cond: (p.product_id = np.product_id)
+         ->  Seq Scan on mergeinto_1.products_row p
+               Output: p.product_id, p.product_name, p.category, p.total, p.ctid
+         ->  Hash
+               Output: np.product_id, np.product_name, np.category, np.total, np.ctid
+               ->  Seq Scan on mergeinto_1.newproducts_row np
+                     Output: np.product_id, np.product_name, np.category, np.total, np.ctid
+(11 rows)
+
 EXPLAIN (VERBOSE on, COSTS off)
 MERGE INTO products_row p
 USING newproducts_row np
@@ -59,26 +80,19 @@ WHEN MATCHED THEN
   UPDATE SET product_name = np.product_name, category = np.category, total = np.total
 WHEN NOT MATCHED THEN  
   INSERT VALUES (np.product_id, np.product_name, np.category, np.total);
-                                                                                                                QUERY PLAN                                                                                                                
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
- Streaming (type: GATHER)
-   Node/s: All datanodes
-   ->  Merge on mergeinto_1.products_row p
-         ->  Streaming(type: REDISTRIBUTE)
-               Output: np.product_id, np.product_name, np.category, np.total, p.product_id, p.product_name, p.category, p.total, p.ctid, p.xc_node_id, np.ctid, (CASE WHEN (p.ctid IS NULL) THEN np.product_id ELSE p.product_id END)
-               Distribute Key: (CASE WHEN (p.ctid IS NULL) THEN np.product_id ELSE p.product_id END)
-               Spawn on: All datanodes
-               Consumer Nodes: All datanodes
-               ->  Nested Loop Left Join
-                     Output: np.product_id, np.product_name, np.category, np.total, p.product_id, p.product_name, p.category, p.total, p.ctid, p.xc_node_id, np.ctid, CASE WHEN (p.ctid IS NULL) THEN np.product_id ELSE p.product_id END
-                     Join Filter: (p.product_id = np.product_id)
-                     ->  Seq Scan on mergeinto_1.newproducts_row np
-                           Output: np.product_id, np.product_name, np.category, np.total, np.ctid
-                           Distribute Key: np.product_id
-                     ->  Seq Scan on mergeinto_1.products_row p
-                           Output: p.product_id, p.product_name, p.category, p.total, p.ctid, p.xc_node_id
-                           Distribute Key: p.product_id
-(17 rows)
+                                                                QUERY PLAN                                                                 
+-------------------------------------------------------------------------------------------------------------------------------------------
+ Merge on mergeinto_1.products_row p
+   ->  Hash Right Join
+         Output: np.product_id, np.product_name, np.category, np.total, p.product_id, p.product_name, p.category, p.total, p.ctid, np.ctid
+         Hash Cond: (p.product_id = np.product_id)
+         ->  Seq Scan on mergeinto_1.products_row p
+               Output: p.product_id, p.product_name, p.category, p.total, p.ctid
+         ->  Hash
+               Output: np.product_id, np.product_name, np.category, np.total, np.ctid
+               ->  Seq Scan on mergeinto_1.newproducts_row np
+                     Output: np.product_id, np.product_name, np.category, np.total, np.ctid
+(10 rows)
 
 -- only MATCHED clause
 MERGE INTO products_row p

src/test/regress/parallel_schedule0

@@ -155,7 +155,7 @@ test: single_node_sequence
 
 # run and check forbidden functions are still forbidden to use in single node
 test: single_node_forbidden
-test: single_node_mergeinto
+test: single_node_mergeinto merge_1
 
 # Trigger tests
 test: single_node_triggers

src/test/regress/sql/merge_1.sql

@@ -64,6 +64,13 @@ ANALYZE products_row;
 ANALYZE newproducts_row;
 
 -- explain verbose
+EXPLAIN (VERBOSE on, COSTS off)
+MERGE INTO products_row p
+USING newproducts_row np
+ON p.product_id = np.product_id
+WHEN MATCHED THEN
+  UPDATE SET product_name = np.product_name, category = np.category, total = np.total where np.product_id = 5;
+
 EXPLAIN (VERBOSE on, COSTS off)
 MERGE INTO products_row p
 USING newproducts_row np