Interesting...CHOOSE means Oracle will decide whether to use RULE or COST. But a
CHOOSE hint will force use of COST. Kind of diminishes the meaning of CHOOSE, doesn't
it? Seems like a pointless hint...
[EMAIL PROTECTED] 05/08/01 11:45PM
If the system is Rule based and you code Hints, the
woo hoo! Bambi's back and we've got her! :)
welcome home, you've been missed
From: Bambi Bellows [EMAIL PROTECTED]
Reply-To: [EMAIL PROTECTED]
To: Multiple recipients of list ORACLE-L [EMAIL PROTECTED]
Subject: Re: consistency in cost?
Date: Wed, 09 May 2001 14:31:01 -0800
Tim --
Oh, sure
Tim --
Oh, sure, bring LOGIC into it. Truth of the matter is that Oracle is trying to phase
out the last vestiges of v5, and that's never EVER going to happen. Logic be dammed!
Mwahahahaha!
Bambi.
--Original Message-
Date: Wed, 09 May 2001 05:01:06 -0800
To: Multiple recipients of
Jared,
The only difference is about a weeks worth of extra data. Well, the hardware
is also different (Ultra450 vs. Ultra 5000. Also 1 vs 4 CPU). But
regardless, shouldn't init.ora optimizer_mode=choose be identical to
optimizer_mode=rule with hint=choose? If I have the time, I'll try to set up
a
me a problem is in production so I have
limited play time there).
Henry
-Original Message-
From: Jared Still [mailto:[EMAIL PROTECTED]]
Sent: Tuesday, May 08, 2001 12:56 AM
To: [EMAIL PROTECTED]; Henry Poras
Subject: Re: consistency in cost?
Henry,
You say 'nearly identical
Forgive my ignorance but I thought hints were only for cost based optimizer.
Have you checked in case anybody has changed any parameters while the system
is running as I know that changing the hash_area_size can change the
execution plan?. Are you using parallelism as if a table had to be
If the system is Rule based and you code Hints, the CBO will be
automatically invoked
Sam
- Original Message -
To: Multiple recipients of list ORACLE-L [EMAIL PROTECTED]
Sent: Tuesday, May 08, 2001 10:12 PM
Forgive my ignorance but I thought hints were only for cost based
optimizer.
Sam,
Thanks for the answer. I am having no trouble invoking the CBO. What is
confusing me is its apparent(?) inconsistency. If I EXPLAIN a query with the
instance using 'CHOOSE' in init.ora I get a different plan than if I EXPLAIN
the same query on the same database on the same hardware with the
I am working with an 8.1.6 database on Solaris 2.6 and I am wondering if
there is any consistency in the optimizer. We have two nearly identical
databases (one a clone from two weeks ago). A five table join has nearly the
identical execution plan on the two databases. The difference is in the
Henry,
You say 'nearly identical'.
What are the differences?
Are the 2 databases on the same platform?
If not, what are the differences, hardware and OS?
Jared
On Monday 07 May 2001 21:55, Henry Poras wrote:
I am working with an 8.1.6 database on Solaris 2.6 and I am wondering if
there
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