[Rt-devel] Slowest query in our setup
rspier at pobox.com
Tue Aug 3 01:33:43 EDT 2004
> For example in this slow query ACL and Groups are restricted by clause:
> ACL_1.PrincipalId = main.id AND ACL_1.PrincipalType = 'Group'
> ) OR (
> main.Type = ACL_1.PrincipalType
> This clause can be split in two and optimized with indexies first on
> ACL(PrincipalId, PrincipalType,...) and second on
> ACL(PrincipalType,...). MySQL can use only one index so it doesn't use
If the index was:
it may be able to use it for both.
(Index Prefix Matching)
More information about the Rt-devel