Re: Performance Tuning

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Mon, 11 Oct 1999 08:53:43 +0100
Message-ID: <939628517.20911.2.nnrp-04.9e984b29@news.demon.co.uk>

It is a commonly held belief still that a 'short table' is one that is 4 (or 5) blocks or less.

This has not been true for a very long time.

A small table is one where the number of blocks is less than parameter (_)small_table_threshold, a parameter which no longer exists in newer versions of Oracle, but which defaulted to 2% of the db_block_buffer figure.

Small tables can be VERY big.

Jonathan Lewis
Yet another Oracle-related web site: http://www.jlcomp.demon.co.uk

michael_bialik_at_my-deja.com wrote in message <7tn9p2$8bf$1_at_nnrp1.deja.com>...
>Hi.
>
> In your application there 70460 FULL TABLE scans
> ( table scanned ( long ) ) of tables with more than 5
> blocks and 38069 FULL table scans ( table scanned ( short))
> with 5 or less blocks.
Received on Mon Oct 11 1999 - 02:53:43 CDT