Re: Sorts and IO in the temporary tablespace

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Thu, 6 Dec 2001 16:15:38 -0000
Message-ID: <1007655218.26003.0.nnrp-08.9e984b29@news.demon.co.uk>

There may be very little connection between the two.

The temporary tablespace is the target for large hash joins, temporary tables, and temporary LOBs in 8.1

Also, a genuine sort that does not 'use the disk' for sorting may also dump the result set to disk anyway at the end of the sort if the sort_area_retained_size is smaller than the sort_area_size.

--
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dias wrote in message <55a68b47.0112060721.3fc814c3_at_posting.google.com>...


>Hi,

>

>I have a big diffrence between the sorts in the SYSSTAT section of a

>report.txt and IO on the temporary tablespace.

>

>- Sorts (disk) = 16

>- Temporary tablespace:

>   - READS = 7794

>   - BLKS_READ = 95301

>   - WRITES = 11999

>   - BLK_WRT = 11999

>

>My question is what is the relation between the number of sorts and

>the IO in the temporary tablespace. Are all IO in the temporary

>tablespace caused by sorts or not ?

>

>Thanks

Received on Thu Dec 06 2001 - 10:15:38 CST