Maybe stupid question about exp/imp

From: Norman Dunbar <Norman.Dunbar_at_lfs.co.uk>
Date: Tue, 15 Apr 2003 11:41:43 +0100
Message-ID: <E2F6A70FE45242488C865C3BC1245DA7038DCC3D@lnewton.leeds.lfs.co.uk>

Jan,

it *used* to be said that importing into a single extent would increase performance, and certain tests *seemed* to show that this was the case. However, this is probably the number one Oracle Mythe of all times.

There may have been a performance benefit, however small, after the import but this is likely to be due to migrated or chained rows being relocated in their 'home' block and not spread all over the countryside.

It has been proved time and again that this is not a 'performance enhancer', but I still have a customer's dba who insists on reorganising his databases every weekend to get all the data into one single extent.

Basically, the answer is no, importing will not produce much in the way of performance benefits.

Cheers,
Norm.

Norman Dunbar
Database/Unix administrator
Lynx Financial Systems Ltd.
mailto:Norman.Dunbar_at_LFS.co.uk

Tel: 0113 289 6265
Fax: 0113 289 3146
URL: http://www.Lynx-FS.com


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-----Original Message-----
From: Jan Gelbrich [mailto:j_gelbrich_at_westfalen-blatt.de] Posted At: Tuesday, April 15, 2003 8:30 AM Posted To: server
Conversation: Maybe stupid question about exp/imp Subject: Maybe stupid question about exp/imp

Hello,

can exp/imp be one way of database tuning at all ? Recently I heard some roumors saying that, after re-importing, there might be a slightly better overall performance, "for some reason".

<SNIP> Received on Tue Apr 15 2003 - 05:41:43 CDT