Re: Performance Issues on 570

[Nelson Smith <ncsmith@xxxxxxxxxxxxxxx>]

Nothing was changed on purpose, at the time.  Of course, everythings 
been changed over and over again now with all the testing going on.

David C. Shea wrote:

> When you migrated, did you do anything to the files like reorganize
> them?  Should you?  Do the files have a lot of deleted records?
>
> I'm assuming that IBM has looked into reorganizing by access path or
> making new access paths...  Were any libraries left out of the move?
> Perhaps the old box had an access path in another library that was
> actually helping you?
>
> Did any of the file's definition change between old and new?  Do a DSPFD
> on both boxes and look for differences.
>
> Do you still have the old box so that you can run some benchmarks?  You
> might want to run in debug on both boxes to see what access paths are
> being used.  I'd also be curious to know the difference in CPU seconds
> between the 2 boxes.
>
> Did you do any application upgrades / conversions that may have
> rearranged the records in the files?  Have you turned on REUSEDLT?  Is
> this green screen or client/server/odbc?  Have you done anything with
> triggers or referential constraints that might be new?
>
> Journaling?  Mirroring?  If journaling, are the receivers in their own
> ASP?  Receivers are essentially sequential writes, so it's nice if
> they're in their on ASP so they don't cause contention with other
> updates.
>
> Have you added any access paths to the physical files involved?  More
> access paths means slower updates...
>
> How were the logical files created on the new box - through a restore or
> through some compile process?  Compiling in the 'wrong' order can cause
> more access paths to be maintained by the system.  Restoring them will
> typically cause the box to decide that LOGICALA can piggyback on
> LOGICALB, etc, causing the system to have to maintain fewer access
> paths.
>
> Good luck.
>
>
>