If you have the 10132 trace - or pull the plan from memory with the other_xml -
there's information about the number (and nothing else) of sql plan directives
viewed and used; but as soon as a directive is replaced by a column group
information the directive is no longer counted.
Regards
Jonathan Lewis
________________________________________
From: oracle-l-bounce@xxxxxxxxxxxxx <oracle-l-bounce@xxxxxxxxxxxxx> on behalf
of Mark W. Farnham <mwf@xxxxxxxx>
Sent: 24 February 2017 20:55:09
To: alfredo.abate@xxxxxxxxx; Amir.Hameed@xxxxxxxxx
Cc: 'Maris Elsins'; tim.evdbt@xxxxxxxxx; oracle-l@xxxxxxxxxxxxx
Subject: RE: Extended database statistics
Regarding whether or not you can see from the plan whether extended stats
helped you arrive at that plan, I’m not aware of anything short of a Wolfgang
trace that shows you what the CBO process was in arriving at the plan.
It would probably be difficult to remove the extended stat columns and re-run
the exact query again to see if you obtained a different plan without them.
And if you’ve got adaptive features activated, good luck telling WHY the plan
changed anyway. I think it checks the race results at Las Vegas. (Not really.
But right now there are more factors going on than I can keep track of and I’m
not even sure which factors are taking place that we cannot see. If there is an
event like the Wolfgang trace that can cause “adaptive” to spit out something
when it makes a change and tells why that might be helpful. I’m not sure
whether adaptive changes are reported in a Millsap trace. I have never seen
them there, but not seeing evidence is not the same as not happening.)
mwf
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On ;
Behalf Of Alfredo Abate
Sent: Friday, February 24, 2017 12:54 PM
To: Amir.Hameed@xxxxxxxxx
Cc: Maris Elsins; tim.evdbt@xxxxxxxxx; oracle-l@xxxxxxxxxxxxx
Subject: Re: Extended database statistics
Amir,
Both Tim and Maris have given you excellent advice already. The only other
thing I will mention is to review MOS doc # 396009.1 to make sure you have the
database initialization parameters set accordingly for EBS.
The parameter you mentioned, OPTIMIZER_ADAPTIVE_FEATURES, is one of these
parameters on the list that needs to be set to FALSE.
Alfredo
On Fri, Feb 24, 2017 at 9:36 AM, Hameed, Amir
<Amir.Hameed@xxxxxxxxx<mailto:Amir.Hameed@xxxxxxxxx>> wrote:
We found thousands of extended statistics on standard tables. According to
Oracle, they are collected if OPTIMIZER_ADAPTIVE_FEATURES is set to TRUE and
this is what I want to validate.
Also, if there a way to find out from an explain plan if extended statistics
were used for the pan?
From: Maris Elsins [mailto:elmaris@xxxxxxxxx<mailto:elmaris@xxxxxxxxx>]
Sent: Friday, February 24, 2017 10:23 AM
To: tim.evdbt@xxxxxxxxx<mailto:tim.evdbt@xxxxxxxxx>
Cc: Hameed, Amir <Amir.Hameed@xxxxxxxxx<mailto:Amir.Hameed@xxxxxxxxx>>;
oracle-l@xxxxxxxxxxxxx<mailto:oracle-l@xxxxxxxxxxxxx>
Subject: Re: Extended database statistics
If I remember right, then the column sets that FND_STATS collect the extended
stats for are defined in FND_EXTNSTATS_COLS (for eBS).
If you have more extended stats than defined in this table, then there's
something else collecting them too.
---
Maris Elsins
@MarisElsins<https://twitter.com/MarisElsins>
www.facebook.com/maris.elsins<https://www.facebook.com/maris.elsins>
On Fri, Feb 24, 2017 at 5:16 PM, Tim Gorman
<tim.evdbt@xxxxxxxxx<mailto:tim.evdbt@xxxxxxxxx>> wrote:
Amir,
In releases of EBS prior to R12.2, patching to FND_STATS might be necessary to
make access to extended statistics available, according to this support white
paper<https://support.oracle.com/epmos/main/downloadattachmentprocessor?attachid=1586374.1%3ADOC1586374_A&docType=WHITE%20PAPER&action=download>.
If those patches have not been applied to FND_STATS, then you can eliminate EBS
from your research.
Hope this helps...
-Tim
On 2/24/17 08:05, Hameed, Amir wrote:
Thanks Tim.
The EBS version is 12.1.3.
From: oracle-l-bounce@xxxxxxxxxxxxx<mailto:oracle-l-bounce@xxxxxxxxxxxxx>
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Tim Gorman
Sent: Friday, February 24, 2017 10:02 AM
To: oracle-l@xxxxxxxxxxxxx<mailto:oracle-l@xxxxxxxxxxxxx>
Subject: Re: Extended database statistics
Amir,
The version of EBS is important to share as well, but since the underlying
database is 12c, I'm guessing it likely that EBS is R12.2.x?
If so, please be aware that the FND_STATS package in EBS R12.2 supports the
gathering of extended
statistics<https://docs.oracle.com/cd/E26401_01/doc.122/e22954/T202991T174306.htm>,
and you may want to check the settings in use to determine if the presence of
the extended statistics is caused by EBS settings, rather than something in the
RDBMS parameters?
Hope this helps...
-Tim
On 2/24/17 07:55, Hameed, Amir wrote:
Hi,
The Oracle database version is 12c (12.1.0.2). The application is Oracle
E-Business Suite.
While working on a performance issue, we discovered that there were a lot of
extended statistics present in the database for standard EBS tables. We do not
create extended statistics on any table as part of our statistics gathering
process. The following parameters were set to TRUE:
optimizer_adaptive_features
optimizer_adaptive_reporting_only
I am trying to understand the following:
1. Does Oracle collect extended statistics automatically if the
optimizer_adaptive_features parameter is set to TRUE?
2. Is there a way to find out from the explain plan if extended
statistics were used in the plan?
Thank you,
Amir
--
//www.freelists.org/webpage/oracle-l
