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RE: RE: Tablespace management.

From: Wolfgang Breitling <>
Date: Fri, 30 May 2003 12:59:47 -0800
Message-ID: <>

To quote the paper:

"Oracle supports an unlimited number of extents in a segment. The performance for DML operations is largely independent of the number of extents in the segment. However, certain DDL operations such as dropping and truncating of segments are sensitive to the number of extents. Performance measures for these operations have shown that a few thousand extents can be supported by Oracle without a significant impact on performance. A reasonable maximum has been determined to be 4096. The goal of our recommended algorithm is to keep the number of extents below 1024 which is well within the range that Oracle can efficiently handle. When a segment reaches 1024 extents it is a candidate to be moved to the next larger extent size tablespace. The segment does not necessarily have to be moved immediately or at all. The segment may be near its peak steady state size, in which case even if it has a few thousand extents, it should be left where it is. It is only the segments which are growing that have to be targeted and potentially moved to tablespaces with larger extents."

A few comments:

At 11:59 AM 5/30/2003 -0800, you wrote:
>The "How To Stop Defragmenting..." paper says it in section 2.1.4.
>Rich Jesse System/Database Administrator
> Quad/Tech International, Sussex, WI USA

Wolfgang Breitling
Oracle7, 8, 8i, 9i OCP DBA
Centrex Consulting Corporation

Please see the official ORACLE-L FAQ:
Author: Wolfgang Breitling

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Received on Fri May 30 2003 - 15:59:47 CDT

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