You cannot specify INSERT DEFAULT VALUES in a MERGE request. MERGE supports UDTs. See “MERGE Insert Operations and UDTs” on page 444 and “MERGE Update Operations and UDTs” on page 444. MERGE can be specified as a triggering action. See “MERGE as a Triggering Action” on page 444 and “CREATE TRIGGER” in SQL Data Definition Language. MERGE cannot be specified as a triggered action. See “MERGE as a Triggered Action” on page 445 and “CREATE TRIGGER” in SQL Data Definition Language.