Correction to -> Re: Does export/import compress (deallocate) extents used by table ?
Date: 6 Aug 92 18:23:03 GMT
Message-ID: <1992Aug6.182303.6887_at_oracle.us.oracle.com>
You are right, Chuck. I am incorrect in stating that compress=y during export will make the initial extent of the create table statement the size of the data. It actually just adds up all the separate extents and uses that as the size. If there's very little data left, then you might just do a create new-table as select * from fragmented-table.
You need to pre-create the table with an initial extent that reflects the actual data that was exported if you want to compress all the unused space.
- Kathy
Received: 08-06-92 10:28 Sent: 08-06-92 09:32 From: Chuck Coulson <HQPYR1:ccoulson_at_us.oracle.com> To: kjou_at_us.oracle.com Subject: Re: Does export/import compress (deallocate) extents used by table ? Cc: kortikar_at_mipos2.intel.com
Reply-To: HQPYR1:ccoulson_at_us.oracle.com Original-To: UNIX:kjou_at_us.oracle.com Original-Cc: UNIX:kortikar_at_mipos2.intel.com
In-Reply-To: ccoulson.US1's message of 08-06-92 09:07
Kathy-
My understanding is that an export will only compress the total number of extents into one extent, but not compress the size of all of the extents. So, if you have table that grows to 10 extents of 10 meg, for a total of 100meg, and then you delete 95% of the records, do an export and an import, you will have table with 1 extent of 100meg.
I believe the best way to do this is to drop an recreate the table with the appropriate storage parameters after the export but before the import.
Chuck Coulson 659509 Sr. Sales Consultant 415.506.5139 OEM/Strategic Accounts ccoulson_at_oracle.com ===============================================================================
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Received: 08-06-92 09:07 Sent: 08-06-92 09:07From: ccoulson.US1
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Subject: Does export/import compress (deallocate) extents used by table ? Reply-To: UNIX:kjou_at_us.oracle.com
Newsgroups: comp.databases.oracle
From: kjou_at_us.oracle.com (Kathy Jou)
Subject: Re: Does export/import compress (deallocate) extents used by table ?
Message-ID: <1992Aug5.192201.29819_at_oracle.us.oracle.com>
Sender: Kathy Jou
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Organization: Oracle Corporation, Redwood Shores CA 94065
References: <12694_at_inews.intel.com>
Date: Wed, 5 Aug 1992 19:22:01 GMT
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In article <12694_at_inews.intel.com> kortikar_at_mipos2.intel.com () writes:
>since oracle does not deallocate extents after a delete of say 95% rows from
>a 50 will export, drop table, import do the trick ?
% exp help=y
The above will give you all the exp command line options and their default settings.
- Kathy Jou
- Oracle Corporation