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Re: Performance problems with large table

From: Jerry Gitomer <jgitomer_at_ictgroup.com>
Date: 1998/03/30
Message-ID: <351FE64A.7480@ictgroup.com>#1/1

Hi Martin,

Before you do anything else check the PCTFREE parameter. If you have not specified otherwise Oracle will take the default (usually around 10%). It sounds like your PCTFREE (which can be set on a table by table basis) should be somewhere around 55%.

Create a new table with the high PCTFREE value and your performance problems should diminish.

Regards

Jerry

Ing. Martin Gamperl wrote:
>
> I created one table with 500 columns and about 84600 records. The first
> column is of type DATE the remaining comlumns are of type NUMBER.
> Columns are added or deleted from the table using triggers when entries
> in other tables change.
> The database was created with a block size of 8K under Windows NT 4.0
> with Oracle Enterprise Server 8.0.3.
> When performing queries response time is very poor! For example a
> "SELECT COUNT(*) ..." needs about 5 minutes to complete.
> At last I used the ANALYZE command with the LIST CHAINED ROWS option to
> determine chained or migrated rows and almost every second row is a
> chained row. So I copied the contents of the whole table to a new table
> to avoid chained rows - but with no success.
> What can we do to increase performance and decrease chained rows. Should
> we change initialization parameters (db_block_size, etc.)?
>
> Please reply to my email address.
>
> Thanxs in advance
>
> Martin
>
> --
> ***************************************************
> * Ing. Martin Gamperl
> * MGS Messgeraetesteuerung - Softwareentwicklung
> * Klosterwiesgasse 31/IV
> * A-8010 GRAZ
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> * Fax : +43-316-83 58 26
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-- 
Jerry Gitomer         	ICT Group
jgitomer_at_ictgroup.com	Langhorne PA
jgitomer_at_p3.net 	Opinions are mine not those of ICT Group
Received on Mon Mar 30 1998 - 00:00:00 CST

Original text of this message

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