Cherie
You could turn it off using _fast_full_scan_enabled=false at the instance level. fast_full_scan_enabled is simply an underscore parameter in 8.1.7. But, I would turn on the event 10053 and run the statement to find why CBO is not using.. Could it be possible that this behaviour is due to poor index selectivity ?
alter session set events '10053 trace name context forever, level 1';
Thanks
Riyaj "Re-yas" Shamsudeen
Certified Oracle DBA
i2 technologies www.i2.com
| [EMAIL PROTECTED]
Sent by: [EMAIL PROTECTED] 09/07/01 06:55 AM
|
To: Multiple recipients of list ORACLE-L <[EMAIL PROTECTED]> cc: Subject: Re: Fast Full Index Scan in 8.1.7 |
I wanted to turn it off in testing so I could try some other indexes as an
alternative. I'm not sure that I trust it to make a good decision.
Even with an alternative index hint, it's not using the index I'm trying to
get it to use, but rather the fast full index scan. I can't see any typo
but
maybe it just can't use that index with full full index scan enabled.
That's why I wanted to try and disable it and see what would happen.
CBO does some interesting things. Every time I think I have a handle
on some aspect of it, it changes and starts doing something different.
Thanks for your reply.
Cherie
Jared Still
<jkstill@cybco To: [EMAIL PROTECTED], [EMAIL PROTECTED]
n.com> cc:
Subject: Re: Fast Full Index Scan in 8.1.7
09/07/01 12:04
AM
The alternative is probably a full table scan.
Are you sure you want to turn it off?
I think you need to hint your SQL to do that.
Jared
On Thursday 06 September 2001 13:21, [EMAIL PROTECTED] wrote:
> I had been using the FAST_FULL_SCAN_ENABLED initialization parameter in
an
> 8.0.4 database.
>
> Apparently this parameter is now obsolete in 8.1.7.2. Seems as though I
> am getting the fast full index
> scans automatically now. I'm not sure if I want them in all cases. Is
> there a way to turn them off?
>
> Thanks,
>
> Cherie Machler
> Oracle DBA
> Gelco Information Network
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