CKPTINTVL configuration parameter

Use the CKPTINTVL configuration parameter to specify the frequency, expressed in seconds, at which the database server checks to determine whether a checkpoint is needed. When a checkpoint occurs, all pages in the shared-memory buffer pool are written to disk.

onconfig.std value
CKPTINTVL 300
values
Any value greater than or equal to 0
units
Seconds
takes effect
After you edit your onconfig file and restart the database server.
When you reset the value dynamically in your onconfig file by running the onmode -wf command.
When you reset the value in memory by running the onmode -wm command.

Usage

The RTO_SERVER_RESTART and CKPTINTVL configuration parameters are mutually exclusive. If the RTO_SERVER_RESTART configuration parameter is enabled, it will trigger checkpoints and CKPTINTVL values are ignored. Otherwise, CKPTINTVL values are used to trigger checkpoints.

If you set the CKPTINTVL configuration parameter to an interval that is too short, the system spends too much time performing checkpoints, and the performance of other work suffers. If you set the CKPTINTVL configuration parameter to an interval that is too long, fast recovery might take too long.

In practice, 30 seconds is the smallest interval that the database server checks. If you specify a checkpoint interval of 0, the database server does not check if the checkpoint interval has elapsed. However, the database server still performs checkpoints. Other conditions, such as the physical log becoming 75 percent full, also cause the database server to perform checkpoints.


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