I am working with ASE 15 in my application and there is performance
issue related with nested joins. I have stored procedure which selects
2 columns from 2 tables and compares equalities of over 10 columns
between this 2 tables. But when I run this stor. proc., the result
takes 40 minutes. I added "set merge-join off" statement to top of my
proc then the result takes 22 seconds. but I need one more solution
without that. I was using sybase ase 12.x before and there was no any
issue like that and my proc was take 3 mins for the result.

I have compared server configurations with sp_configure between 15 and
12.x and sybase ase15 server configurations (I/O and memory
configuration settings) are bigger than sybase ase 12.x server.

Info: sybase15 located pc's system resources are really good.

In ASE 15, you will need to figure out the proper "optimization goal" for
which your queries run best. Also, it is extremely important that you have
proper statistics on your tables, and typically the requirement here is
higher than was the case in 12.5.
I recommend you read the following whitepapers:
http://www.sybase.com/detail?id=1056243 and
http://www.sybase.com/detail?id=1063556 .

BTW, "set sort_merge off" has no effect anymore in ASE 15, unless you're
using 'compatibility mode'.

There's more information about ASE 15 migration at
www.sybase.com/ase15upgrade

HTH,
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Rob Verschoor

Certified Sybase Professional DBA for ASE 15.0/12.5/12.0/11.5/11.0
and Replication Server 15.0.1/12.5 // TeamSybase

Author of Sybase books (order online at www.sypron.nl/shop):
"Tips, Tricks & Recipes for Sybase ASE" (ASE 15 edition)
"The Complete Sybase ASE Quick Reference Guide"
"The Complete Sybase Replication Server Quick Reference Guide"

mailto:rob (AT) sypron (DOT) nl
http://www.sypron.nl
Sypron B.V., Amersfoort, The Netherlands
Chamber of Commerce 27138666
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"aykut" <maykutsay (AT) gmail (DOT) com> wrote