Revert "Modified files for MERGE"

This reverts commit 354f13855e.

src/pl/plpgsql/src/pl_exec.c

@@ -3967,7 +3967,7 @@ exec_stmt_execsql(PLpgSQL_execstate *estate,
 
 	/*
 	 * On the first call for this statement generate the plan, and detect
-	 * whether the statement is INSERT/UPDATE/DELETE/MERGE
+	 * whether the statement is INSERT/UPDATE/DELETE
 	 */
 	if (expr->plan == NULL)
 	{
@@ -3988,7 +3988,6 @@ exec_stmt_execsql(PLpgSQL_execstate *estate,
 				{
 					if (q->commandType == CMD_INSERT ||
 						q->commandType == CMD_UPDATE ||
-						q->commandType == CMD_MERGE ||
 						q->commandType == CMD_DELETE)
 						stmt->mod_stmt = true;
 				}
@@ -4046,7 +4045,6 @@ exec_stmt_execsql(PLpgSQL_execstate *estate,
 		case SPI_OK_INSERT_RETURNING:
 		case SPI_OK_UPDATE_RETURNING:
 		case SPI_OK_DELETE_RETURNING:
-		case SPI_OK_MERGE:
 			Assert(stmt->mod_stmt);
 			exec_set_found(estate, (SPI_processed != 0));
 			break;
@@ -4224,7 +4222,6 @@ exec_stmt_dynexecute(PLpgSQL_execstate *estate,
 		case SPI_OK_INSERT_RETURNING:
 		case SPI_OK_UPDATE_RETURNING:
 		case SPI_OK_DELETE_RETURNING:
-		case SPI_OK_MERGE:
 		case SPI_OK_UTILITY:
 		case SPI_OK_REWRITTEN:
 			break;

src/pl/plpgsql/src/pl_gram.y

@@ -304,7 +304,6 @@ static	void			check_raise_parameters(PLpgSQL_stmt_raise *stmt);
 %token <keyword>	K_LAST
 %token <keyword>	K_LOG
 %token <keyword>	K_LOOP
-%token <keyword>	K_MERGE
 %token <keyword>	K_MESSAGE
 %token <keyword>	K_MESSAGE_TEXT
 %token <keyword>	K_MOVE
@@ -1948,10 +1947,6 @@ stmt_execsql	: K_IMPORT
 					{
 						$$ = make_execsql_stmt(K_INSERT, @1);
 					}
-				| K_MERGE
-					{
-						$$ = make_execsql_stmt(K_MERGE, @1);
-					}
 				| T_WORD
 					{
 						int			tok;
@@ -2474,7 +2469,6 @@ unreserved_keyword	:
 				| K_IS
 				| K_LAST
 				| K_LOG
-				| K_MERGE
 				| K_MESSAGE
 				| K_MESSAGE_TEXT
 				| K_MOVE
@@ -2936,8 +2930,6 @@ make_execsql_stmt(int firsttoken, int location)
 		{
 			if (prev_tok == K_INSERT)
 				continue;		/* INSERT INTO is not an INTO-target */
-			if (prev_tok == K_MERGE)
-				continue;		/* MERGE INTO is not an INTO-target */
 			if (firsttoken == K_IMPORT)
 				continue;		/* IMPORT ... INTO is not an INTO-target */
 			if (have_into)

src/pl/plpgsql/src/pl_scanner.c

@@ -138,7 +138,6 @@ static const ScanKeyword unreserved_keywords[] = {
 	PG_KEYWORD("is", K_IS, UNRESERVED_KEYWORD)
 	PG_KEYWORD("last", K_LAST, UNRESERVED_KEYWORD)
 	PG_KEYWORD("log", K_LOG, UNRESERVED_KEYWORD)
-	PG_KEYWORD("merge", K_MERGE, UNRESERVED_KEYWORD)
 	PG_KEYWORD("message", K_MESSAGE, UNRESERVED_KEYWORD)
 	PG_KEYWORD("message_text", K_MESSAGE_TEXT, UNRESERVED_KEYWORD)
 	PG_KEYWORD("move", K_MOVE, UNRESERVED_KEYWORD)

src/pl/plpgsql/src/plpgsql.h

@@ -846,8 +846,8 @@ typedef struct PLpgSQL_stmt_execsql
 	PLpgSQL_stmt_type cmd_type;
 	int			lineno;
 	PLpgSQL_expr *sqlstmt;
-	bool		mod_stmt;		/* is the stmt INSERT/UPDATE/DELETE/MERGE?
-								 * Note mod_stmt is set when we plan the query */
+	bool		mod_stmt;		/* is the stmt INSERT/UPDATE/DELETE?  Note:
+								 * mod_stmt is set when we plan the query */
 	bool		into;			/* INTO supplied? */
 	bool		strict;			/* INTO STRICT flag */
 	PLpgSQL_variable *target;	/* INTO target (record or row) */