Re: default for oracle 7.x with respect to optimizer

From: Mike Mountjoy <michael_at_london.virgin.net>
Date: Thu, 27 Jan 2000 15:13:18 +0000
Message-ID: <3890608E.985ABBE2@london.virgin.net>

The default is RULES based mode in ORA 7 and CHOOSE in ORA 8

The database switches to CHOOSE mode when you issue the command

ANALYZE TABLE <table_name> COMPUTE STATISTICS.

Regrds,
Mike

Jeff Kish wrote:

> Can someone tell me where to find (I looked the docs over, honest)
> what the default is for Oracle 7.x as far as optimizer_mode ?
> I believe you can put a number of parameters in the initorcl.ora file
> to set this, but I don't know what the system does if the parameter is
> missing.
>
> Oracle 8, I found out, defaults to "optimizer_mode=choose", unless
> statitistics are not available. In that case it uses rule-based
> instead.
>
> Thanks
> Jeff Kish
> kishj_at_concentric.net
> jeff.kish_at_ait-mmii.com
Received on Thu Jan 27 2000 - 09:13:18 CST

Re: default for oracle 7.x with respect to optimizer_mode