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rebuilding indexes ..!!! [message #141041] Thu, 06 October 2005 13:59 Go to next message
balavignesh
Messages: 180
Registered: March 2005
Senior Member
hai,

we have a client with 8i under linux.
they are using the app and is slow today.
the particular part of the app is freezing and the tables involved have lacs of records and also indexed.

Will there be any increase in the performance if we rebuild the indexes ..?

or else how to increase the performance ...?

plz help out.

regards
bala
Re: rebuilding indexes ..!!! [message #141042 is a reply to message #141041] Thu, 06 October 2005 14:11 Go to previous messageGo to next message
Mahesh Rajendran
Messages: 10708
Registered: March 2002
Location: oracleDocoVille
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>>Will there be any increase in the performance if we rebuild the indexes ..?
May be.
May not be. It is not going to get you anywhere.

Did you update the statistics?
Re: rebuilding indexes ..!!! [message #141046 is a reply to message #141042] Thu, 06 October 2005 14:29 Go to previous messageGo to next message
balavignesh
Messages: 180
Registered: March 2005
Senior Member
we need to clarify ourself.

we have gathered the statistics to trigger the CBO.But immediately after it was done , the application is freezing and so we deleted the statistics and now it is working and not too fast.but when we did the same for a 9i server , it is working good.

why is it so...?

for 8i server itself , the optimizer mode is choose (CBO).

So , gathering stats for the objects in 8i will cause adverse effects in app...?

if so, how to improve performance other than gathering stats..?
Re: rebuilding indexes ..!!! [message #141050 is a reply to message #141046] Thu, 06 October 2005 14:35 Go to previous messageGo to next message
Mahesh Rajendran
Messages: 10708
Registered: March 2002
Location: oracleDocoVille
Senior Member
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>>the application is freezing
Check why the application is freezing.
THere must be some kind of wait events reported.
Check which particular module/part/sql is causing the trouble.
Re: rebuilding indexes ..!!! [message #141065 is a reply to message #141041] Thu, 06 October 2005 15:24 Go to previous message
smartin
Messages: 1803
Registered: March 2005
Location: Jacksonville, Florida
Senior Member
You really shouldn't be doing all of these changes in production. Get yourself a test copy to work with.

It could be that the app was designed to not have statistics. But we really have no way of knowing, we don't have enough information to help.

Did it all of a sudden start freezing? What was changed right before the freeze first happened? Undo that.
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