Illustration strms013.gif shows an apply process dequeuing LCRs and messages from the queue and either applying messages directly or passing messages to an apply handler. The apply handlers include a message handler procedure to process user messages, a DML handler procedure to process certain DML LCRs (row LCRs), a DDL handler procedure to process DDL LCRs, and a precommit handler to record commit information for LCRs or messages.