COPY (INSERT/UPDATE/DELETE .. RETURNING ..)

Attached is a patch for being able to do COPY (query) without a CTE.

Author: Marko Tiikkaja
Review: Michael Paquier

src/include/nodes/parsenodes.h

@@ -1680,7 +1680,8 @@ typedef struct CopyStmt
 {
 	NodeTag		type;
 	RangeVar   *relation;		/* the relation to copy */
-	Node	   *query;			/* the SELECT query to copy */
+	Node	   *query;			/* the query (SELECT or DML statement with
+								 * RETURNING) to copy */
 	List	   *attlist;		/* List of column names (as Strings), or NIL
 								 * for all columns */
 	bool		is_from;		/* TO or FROM */