RE: Drop Index takes longer in Prod than in Test

  • From: "Mark W. Farnham" <mwf@xxxxxxxx>
  • To: <somckit.khemmanivanh@xxxxxxxxxxxxxxxx>, <oracle-l@xxxxxxxxxxxxx>
  • Date: Wed, 13 Sep 2006 14:16:35 -0400

We'll need version information and whether the tablespaces holding the
indexes are dictionary managed or locally managed.


Are the indexes partitioned or indexes of partitions, etc., etc..


It may be possible for you to speed things up by taking the index
tablespaces offline and doing an offline drop including contents, if the
problem is the pecimal freeing of index extents from a dictionary managed
tablespace.  If the load process you cannot touch does not specify extent
allocations, you may be able to speed things up by changing the space
defaults on the index tablespace(s) to use very few extents (because the
drop can be slow in adding extents back to the free space on dictionary
managed tablespaces.) You also may benefit from moving to locally managed


But these are all wild guesses without knowing a lot more.


Good luck,





From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]
On Behalf Of Khemmanivanh, Somckit
Sent: Wednesday, September 13, 2006 1:17 PM
To: oracle-l@xxxxxxxxxxxxx
Subject: Drop Index takes longer in Prod than in Test




We have a DW nightly load that drops indexes as part of the load. 


The index drops can sometimes take minutes in prod -- whereas as test of the
same drop, in the test environment, takes seconds. Now minutes might not
seem like much, but there are many indexes so the times add up.


I can't easily enable tracing on the Oracle side (prod server, multi-tiered
env, etc...) so I'm looking for some tips for where/what else I can look


Oh, the other constraint is that I can't modify the DW load process -- so
I'm restricted solely to looking at the Oracle side.


Your help is much appreciated.


Thank you!

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