On Tue, Jul 6, 2010 at 10:34 AM, Michael Scheidell <scheid...@secnap.net> wrote: > partition_tag is a key, yes use it, and DON'T use 'in' (as: > partition_tag in (18,19) > or partition_tag between, etc. some versions of mysql mess optimization up. >
I tried it out by adding the active (3) partition tags to the same query. The speed was virtually identical & still slow. When using EXPLAIN, it reports it's not choosing to use the partition tag key but does recognize that it is available. Understandably because adding in the partition_tag qualifier merely tells MySQL to only look at the only data that's there. It doesn't narrow anything down since the rest of the partitions are empty sets anyway. I notice your partitioning scheme is similar (or maybe the same) as amavisd documentation. Other than limiting the total number of partitions using this method, I didn't see a practical reason to use that documented suggestion. That's why we chose to just give each week it's own partition numbered by the week #. It made the cleanup scripts a breeze to write and easy to understand. I also wanted the flexibility of changing our storage policy up or down without having to re-do the partitions from scratch. - N ------------------------------------------------------------------------------ This SF.net email is sponsored by Sprint What will you do first with EVO, the first 4G phone? Visit sprint.com/first -- http://p.sf.net/sfu/sprint-com-first _______________________________________________ AMaViS-user mailing list AMaViS-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/amavis-user Please visit http://www.ijs.si/software/amavisd/ regularly For administrativa requests please send email to rainer at openantivirus dot org
