Configuration parameters that affect page cleaning

Several configuration parameters, including the CLEANERS and RTO_SERVER_RESTART configuration parameters, affect page cleaning. If pages are not cleaned often enough, an sqlexec thread that performs a query might be unable to find the available pages that it needs.

If the sqlexec thread cannot find the available pages that it needs, the thread initiates a foreground write and waits for pages to be freed. Foreground writes impair performance, so you should avoid them. To reduce the frequency of foreground writes, increase the number of page cleaners or decrease the threshold for triggering a page cleaning.

Use onstat -F to monitor the frequency of foreground writes.