[rt-users] Displaying a Ticket is slow - Element "more about this user" - rt 3.4.1

[Tobias Heinz]

Dear All,

my users are complaining about a slow system: Tickets display takes more 
than 12 secs sometimes hitting up to 30 Secs.

I located the source of the slowlyness in the Element "More about ...." 
(/html/Ticket/Elements/ShowRequestor ) and eliminating the "this user's 
10 highest priority tickets" reduces page loading times to below 4 secs.

Unfortunately this functionality is very important to my users.

I am using a postgresql (debian stable - postgreSQL 7.4) - backend 
located on a seperate dedicated DB machine (Quad Dual Core XEONs). rt 
runs on a debian box - stable package for rt ver 3.4.1  (Quad Single 
Core Xeons).

Analysing the queries shows that those queries run quite long (this one 
nearly 6 secs):

2007-01-04 09:28:26 CET rtuser rt01.azd.dg-i.net(60488) rtdb 18884 
4597ae43.49c4 LOG:  duration: 5804.185 ms  statement: SELECT DISTINCT 
main.* FROM Tickets main , Groups Groups_1, CachedGroupMembers 
CachedGroupMembers_2, Users Users_3  WHERE 
((CachedGroupMembers_2.MemberId = Users_3.id)) AND ((Groups_1.Domain = 
'RT::Ticket-Role')) AND ((Groups_1.id = CachedGroupMembers_2.GroupId)) 
AND ((main.EffectiveId = main.id)) AND ((main.Status != 'deleted')) AND 
((main.id = Groups_1.Instance)) AND ( (  ( (LOWER(Users_3.EmailAddress) 
= 'kai.wissler at web.de') AND (Groups_1.Type = 'Requestor') )  )  AND  ( 
(main.Status = 'resolved') OR (main.Status = 'new') OR (main.Status = 
'open') ) )  ORDER BY main.Priority DESC  LIMIT 10

Is there a chance to speed up the queries? Does anyone have an idea how 
to speed up the system or what I could tune? Would upgrading to request 
tracker 3.6 help?

Best regards

Tobias Heinz