checkpoint

You can use checkpoint with an archive database, however, the checkpoint process does not automatically checkpoint an archive database.

Use checkpoint only as a precautionary measure in special circumstances.

sp_dboption automatically defaults to using checkpoint when you change a database option.

You can specify one or more databases to run checkpoint.

Checkpoints caused by the checkpoint command supplement automatic checkpoints, which occur at intervals calculated by the SAP ASE server on the basis of the configurable value for maximum acceptable recovery time.

checkpoint shortens the automatic recovery process by identifying a point at which all completed transactions are guaranteed to have been written to the database device. A typical checkpoint takes about 1 second, although checkpoint time varies, depending on the amount of activity on the SAP ASE server.

The automatic checkpoint interval is calculated by the SAP ASE server on the basis of system activity and the recovery interval value in the system table syscurconfigs. The recovery interval determines checkpoint frequency by specifying the maximum amount of time it should take for the system to recover. Reset this value by executing sp_configure.

You can configure the SAP ASE server with multiple checkpoint processes. This allows the SAP ASE server with multiple engines to checkpoint tasks more frequently, thereby shortening the automatic recovery process.

If the housekeeper task can flush all active buffer pools in all configured caches during the server’s idle time, it wakes up the checkpoint task. The checkpoint task determines whether it can checkpoint the database.

Checkpoints that occur as a result of the housekeeper task are known as free checkpoints. They do not involve writing many dirty pages to the database device, since the housekeeper task has already done this work. They may improve recovery speed for the database.