Writing Restart Records to a CLFS Stream

There are two types of records in a Common Log File System (CLFS)stream: data records and restart records. This topic explains how to write restart records to a CLFS stream. For information about how to write data records, see Writing Data Records to a CLFS Stream.

Typically, restart records are written to a stream periodically to create checkpoints that help make recovery more efficient in the event of a system failure. Assume that you have already created a marshalling area and written several data records. You can then write a restart record by calling ClfsWriteRestartArea. By setting the fFlags parameter, you can specify whether the restart record is placed in the marshalling area's reserved space or in newly allocated space.When CLFS writes a restart record to a stream, it automatically sets the previous LSN of the record to the LSN of the previously written restart record for that stream. That forms a chain of restart records that can be traversed in reverse order. For information about reading the chain of restart records, see Reading Restart Records from a CLFS Stream.

If you want to write a restart record to a stream and change the base LSN of the stream at the same time, set the plsnBase parameter of ClfsWriteRestartArea to the new base LSN.


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