Archives of the TeradataForum
Message Posted: Wed, 19 May 2004 @ 08:21:39 GMT
| Subj: | | Re: Packdisk and system performance |
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| From: | | Martin O Brien |
Regular packdisks can enhance query performance ( especially when you're system becomes more full ). Queries need free cylinders for the spool
that they are going to use ( as spool can only use free cylinders - spool and permanent space can not reside on the same cylinder )... If there
are no more free cylinders and spool requires more, then behind the scene Teradata starts running cylpacks and defrags to try and free up
cylinders. Cylpacks are quite resource intensive and if avoided should not run at busy times. By running regular packdisks ( at quiet times ) you
can reduce cylpacks and defrags running at potentially busy times.
You can check the running of cylpacks and defrags through the system view dbc.ResUsageSvpr ( columns FileMCylPacks & FileCylDefrags ).
Martin
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