Merge 29858d70f9 into 5ce353b76c

src/backend/distributed/commands/multi_copy.c

@@ -346,6 +346,9 @@ static LocalCopyStatus GetLocalCopyStatus(void);
 static bool ShardIntervalListHasLocalPlacements(List *shardIntervalList);
 static void LogLocalCopyToRelationExecution(uint64 shardId);
 static void LogLocalCopyToFileExecution(uint64 shardId);
+#if PG_VERSION_NUM >= PG_VERSION_15
+static void ErrorIfMergeInCopy(CopyStmt *copyStatement);
+#endif
 
 
 /* exports for SQL callable functions */
@@ -2828,6 +2831,25 @@ CopyStatementHasFormat(CopyStmt *copyStatement, char *formatName)
 }
 
 
+#if PG_VERSION_NUM >= PG_VERSION_15
+
+/*
+ * ErrorIfMergeInCopy Raises an exception if the MERGE is called in the COPY.
+ */
+static void
+ErrorIfMergeInCopy(CopyStmt *copyStatement)
+{
+	if (!copyStatement->relation && (IsA(copyStatement->query, MergeStmt)))
+	{
+		ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						errmsg("MERGE not supported in COPY")));
+	}
+}
+
+
+#endif
+
+
 /*
  * ProcessCopyStmt handles Citus specific concerns for COPY like supporting
  * COPYing from distributed tables and preventing unsupported actions. The
@@ -2838,6 +2860,10 @@ Node *
 ProcessCopyStmt(CopyStmt *copyStatement, QueryCompletion *completionTag, const
 				char *queryString)
 {
+	#if PG_VERSION_NUM >= PG_VERSION_15
+	ErrorIfMergeInCopy(copyStatement);
+	#endif
+
 	/*
 	 * Handle special COPY "resultid" FROM STDIN WITH (format result) commands
 	 * for sending intermediate results to workers.

src/backend/distributed/planner/merge_planner.c

@@ -97,6 +97,7 @@ static DistributedPlan * CreateNonPushableMergePlan(Oid targetRelationId, uint64
 													plannerRestrictionContext,
 													ParamListInfo boundParams);
 static char * MergeCommandResultIdPrefix(uint64 planId);
+static void ErrorIfMergeHasReturningList(Query *query);
 
 #endif
 
@@ -949,9 +950,24 @@ ConvertSourceRTEIntoSubquery(Query *mergeQuery, RangeTblEntry *sourceRte,
 }
 
 
+/*
+ * ErrorIfMergeHasReturningList raises an exception if the MERGE
+ * has a RETURNING clause.
+ */
+static void
+ErrorIfMergeHasReturningList(Query *query)
+{
+	if (query->returningList)
+	{
+		ereport(ERROR, (errmsg("MERGE with RETURNING is not yet supported")));
+	}
+}
+
+
 /*
  * ErrorIfMergeNotSupported Checks for conditions that are not supported in either
  * the routable or repartition strategies. It checks for
+ * - MERGE with a RETURNING clause
  * - Supported table types and their combinations
  * - Check the target lists and quals of both the query and merge actions
  * - Supported CTEs
@@ -959,6 +975,7 @@ ConvertSourceRTEIntoSubquery(Query *mergeQuery, RangeTblEntry *sourceRte,
 static void
 ErrorIfMergeNotSupported(Query *query, Oid targetRelationId, List *rangeTableList)
 {
+	ErrorIfMergeHasReturningList(query);
 	ErrorIfMergeHasUnsupportedTables(targetRelationId, rangeTableList);
 	ErrorIfMergeQueryQualAndTargetListNotSupported(targetRelationId, query);
 	ErrorIfUnsupportedCTEs(query);

src/test/regress/expected/pgmerge.out

@@ -174,9 +174,21 @@ COPY (
   WHEN MATCHED THEN DELETE
 ) TO stdout;
 ERROR:  MERGE not supported in COPY
+-- used in a CTE with RETURNING
+WITH foo AS (
+  MERGE INTO target USING source ON (true)
+  WHEN MATCHED THEN DELETE RETURNING target.*
+) SELECT * FROM foo;
+ERROR:  syntax error at or near "RETURNING"
+-- used in COPY with RETURNING
+COPY (
+  MERGE INTO target USING source ON (true)
+  WHEN MATCHED THEN DELETE RETURNING target.*
+) TO stdout;
+ERROR:  syntax error at or near "RETURNING"
 -- unsupported relation types
 -- view
-CREATE VIEW tv AS SELECT * FROM target;
+CREATE VIEW tv AS SELECT count(tid) AS tid FROM target;
 MERGE INTO tv t
 USING source s
 ON t.tid = s.sid

src/test/regress/sql/pgmerge.sql

@@ -126,10 +126,20 @@ COPY (
   MERGE INTO target USING source ON (true)
   WHEN MATCHED THEN DELETE
 ) TO stdout;
+-- used in a CTE with RETURNING
+WITH foo AS (
+  MERGE INTO target USING source ON (true)
+  WHEN MATCHED THEN DELETE RETURNING target.*
+) SELECT * FROM foo;
+-- used in COPY with RETURNING
+COPY (
+  MERGE INTO target USING source ON (true)
+  WHEN MATCHED THEN DELETE RETURNING target.*
+) TO stdout;
 
 -- unsupported relation types
 -- view
-CREATE VIEW tv AS SELECT * FROM target;
+CREATE VIEW tv AS SELECT count(tid) AS tid FROM target;
 MERGE INTO tv t
 USING source s
 ON t.tid = s.sid