Forum OpenACS Q&A: Performance Problems - slow queries!

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Posted by Rocael Hernández Rizzardini on
We're seeing as well slow performance of some queries, even if our box is idle at the time of the request (dual xeon 3.0Ghz with 4GB RAM, DB only).
Mostly happening with permissions, but some other queries are very slow in a portlet fashion (lors, calendar, fs).

When checking the permission, I have seen that when the result will return 0, meaning denied permission, it takes about 1500msec to return the query. (acs_permissions rows 1679466)

One thing that improved our performance on that specific issue with permissions is that we extended the life of the permission for 1 day (kernel param-> PermissionCacheTimeout), although that is not a fix or a real enhancement in the DB side. Always check that the chache amount designated to memoize is big enough, if not you'll end having a lot of flushing (kernel param-> MaxSize), check your memoize hit rate at:
/acs-admin/cache/