Re: Too-frequent checkpoints; which parameters to check?

Bob Cunningham wrote: > > I've got a situation with On-Line 7.22 (SPARC, Solaris 2.5.1) where > we get flurries of checkpoints at short intervals, during > some update periods that look like: > > 23:35:07 Checkpoint Completed: duration was 2 seconds. > 23:35:14 Checkpoint Completed: duration was 1 seconds. > 23:35:22 Checkpoint Completed: duration was 1 seconds. > 23:35:30 Checkpoint Completed: duration was 1 seconds. > 23:35:38 Checkpoint Completed: duration was 1 seconds. > 23:35:46 Checkpoint Completed: duration was 2 seconds. > 23:35:53 Checkpoint Completed: duration was 1 seconds. > ... > 23:45:06 Checkpoint Completed: duration was 1 seconds. > 23:45:14 Checkpoint Completed: duration was 1 seconds.> > Needless to say, queries slow to a crawl when there's > a checkpoint every few seconds. > > Log files aren't a problem, but I'm not sure exactly what is... > > Which tuning parameters should I be looking to change: > PHYSFILE, the LRU* ones, or ??? there are three conditions that will trigger a checkpoint: 1) the interval has specified by ckptintvl has elapsed. 2) the physical logs are 75% full 3) the next logical log has the most recent checkpoint record in your case I would look at number 2.