Re: ANY IDEA ON USING INDEX FOR ORDER BY
Posted in 1998
Hi Felix
Thanks for the tip.
in our case the OPTCOMPIND was already set to 0, but the problem still =
occurred.
The funny thing was that if I dropped and recreated the 'bad' index. It =
moved from being the 'first' index reported by dbschema, to being the =
'last' index reported by dbschema. Then the RDBMS would not use it, but =
would use the other ('good') one.
After coming back to work on Monday the index order, as reported by =
dbschema, had the 'bad' index first again.
(Over the weekend 'update statistics' had run. I cannot think of anything =
else that would affect it).
Now that the 'bad' index was first in the list again, everything slowed =
down again. Tech support tell me it should make no difference - go =
figger.
In the end I just dropped the 'bad' index altogether, and things are =
speedy again.
I have a job on me to get to the bottom of this. I will post any =
revelations that [may] occur.
Cheers
Peter
>>> Felix Koshy Mathews <fmathews@systems.DHL.COM> 16/01/98 08:38:57 >>>
Do you think the optimizer is the one taking you for this wild ride, then =
set your config-file with
OPTCOMPIND 0 # =To hint the optimizer
If it is set to 1 or 2 the optimer will try its best give you better =
performance, but for us it was a waist of time. So we decided to set =
OPTCOMPIND to 0. If I do a query on our tables, it uses the index-key =
similar to your file-id.
--
Have a nice day
Felix K. Mathews
mailto:fmathews@systems.dhl.com=20