Hi Mark, > Does the MySQL query cache actually work? I have heard various things > to the contrary, but haven't actually used it in production, so I > don't know for certain.
It depends. The query cache increases the amount of work that has to be done - reads have to check the cache first and update it after a miss, and writes have to check and invalidate the cache if necessary. So there is some overhead there, and obviously the query cache won't improve the data transfer time back to your app. The queries that work best with the cache are ones that are relatively expensive to generate, but where the result set's small - like aggregate queries. So it really depends on what you're doing. You can check your cache hit rate to get a benchmark of how effective it is by looking at the status variables: Qcache_hits / (Qcache_hits + Com_select) Kind regards, James McGlinn __________________________________ CTO Eventfinder Limited Suite 106, Heards Building 2 Ruskin Street, Parnell, Auckland 1052 Phone: +649 365 2342 Mobile: +6421 633 234 [EMAIL PROTECTED] | www.eventfinder.co.nz --~--~---------~--~----~------------~-------~--~----~ NZ PHP Users Group: http://groups.google.com/group/nzphpug To post, send email to [email protected] To unsubscribe, send email to [EMAIL PROTECTED] -~----------~----~----~----~------~----~------~--~---
