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Re: ORA 8 optimizer really bad!

From: <yong321_at_yahoo.com>
Date: Thu, 27 Jan 2000 23:35:04 GMT
Message-ID: <86qkn8$22b$1@nnrp1.deja.com>


When everything else fails, try Rule optimizer mode.

By the way, you can't say if there's an index, Oracle should always use it. There're so many cases where using indexes is worse, e.g. when a query returns 25% or more rows..

--
Yong Huang

(yong321_at_yahoo.com)
(http://www.stormloader.com/yonghuang/)

In article <86q951$lp3_at_journal.concentric.net>,   "Daniel" <delj_at_flash.net> wrote:
> I see.... the database is not just supposed to use the indexes you
create.
> I understand what you are saying but this is an RDBMS. All of this is
> supposed to be automatic. It has been automatic. If I do a select
> somefield from sometable where somekey = 'somevalue'; the database
should
> use the index if it is there. That is the primary purpose of having
an
> optimizer. My point is, I never had to do this in Oracle 7.x. I am
having
> to do this in 8.x. In addition, some of the optimizer problems were
not
> resolved by computing statistics. I had to have the hints to tell
Oracle
> that there was an index.... This is the way it is supposed to work?
>
> Daniel
> Austin, TX

Sent via Deja.com http://www.deja.com/
Before you buy. Received on Thu Jan 27 2000 - 17:35:04 CST

Original text of this message

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