Re: Gathering of Statistics

Hi Ronnie

Preserving old statistics in a stattab so that you can revert to them in the event f an error or problem seems to me like a perfectly prudent approach. There's clearly been some thought by the vendor because of the decision to gather histograms on every indexed column. It does seem rather likely however that that is overkill - I can think of examples where it *might* be appropriate though. It seems to me though that if you can determine who the company's Oracle expert is you have the basis for a discussion around revising the stats gathering strategy.

Niall

On Jan 26, 2008 7:41 AM, Ronnie Doggart <ronnie_doggart_at_lagan.com> wrote:

> Andrew,
>
> Do you keep a copy of the stats before running the procedure to gather the
> new stats?. What would you do if the performance dropped after gathering the
> stats.
>
> Ronnie
> ________________________________
> From: oracle-l-bounce_at_freelists.org [oracle-l-bounce_at_freelists.org] On
> Behalf Of Andrew Kerber [andrew.kerber_at_gmail.com]
> Sent: 25 January 2008 15:28
> To: Ronnie Doggart
> Cc: jack_at_vanzanen.com; oracle-l_at_freelists.org
> Subject: Re: Gathering of Statistics
>
> I would seriously demand an explanation from the supplier. I received
> instructions to run an almost identical command daily from one of my
> suppliers, and it works perfectly. Keeps the performance right where it
> should be. ymmv.
>
> On Jan 25, 2008 8:52 AM, Ronnie Doggart <ronnie_doggart_at_lagan.com<mailto:
> ronnie_doggart_at_lagan.com>> wrote:
> If the supplier gave the following statement:
>
> Dbms_stats.gather_schema_stats(ownname=>user,cascade=>true,method_opt=>'FOR
> ALL INDEXED COLUMNS SIZE 254')
>
> And said to run it once a week, would you do it.
>
> The reason I ask is the supplier did supply the statement to run and told
> us to run it once a week. But after running it a week ago the performance of
> the application dropped to become almost unusable. The drop in performance
> occurred after gathering the stats. When asked for assistance they told us
> to rerun the statement and it should fix the problem. But the statement is
> the problem.
>
> Ronnie
>
> ________________________________________
> From: oracle-l-bounce_at_freelists.org<mailto:oracle-l-bounce_at_freelists.org>
> [mailto:oracle-l-bounce_at_freelists.org<mailto:oracle-l-bounce_at_freelists.org>]
> On Behalf Of Andrew Kerber
> Sent: 25 January 2008 13:30
> To: jack_at_vanzanen.com<mailto:jack_at_vanzanen.com>
> Cc: Ronnie Doggart; oracle-l_at_freelists.org<mailto:oracle-l_at_freelists.org>
> Subject: Re: Gathering of Statistics
>
> I agree. The vendor should be able to provide information about where and
> when, but you have to provide the script.
>
> Siebel is notorious for needing special consideration when gathering
> statistics.
> On Jan 25, 2008 6:10 AM, Jack van Zanen <jack_at_vanzanen.com<mailto:
> jack_at_vanzanen.com>> wrote:
> I do not expect them to supply the scripts, however I do expect them to be
> able to supply the information needed for proper statistics.
>
> It often is a futile expectation though.
>
>
> Jack
>
>
> On 25/01/2008, Ronnie Doggart <ronnie_doggart_at_lagan.com<mailto:
> ronnie_doggart_at_lagan.com>> wrote:
> Hi All,
>
> If you purchase an application from a supplier would you expect them to
> supply a script for gathering statistics on their schema and to make
> recommendations on how frequently the statistics should be gathered ?
>
> Ronnie
>
>
>
> The information in this message is confidential and may be legally
> privileged. It is intended solely for the addressee. Access to this message
> by anyone else is unauthorised. If you are not the intended recipient, any
> disclosure, copying, or distribution of the message, or any action or
> omission taken by you in reliance on it, is prohibited and may be unlawful.
> Please immediately contact the sender if you have received this message in
> error.
>
> The views and opinions expressed in this email may not reflect the views
> and opinions of any member of Lagan Technologies Limited, or any of its
> subsidiaries.
>
> Lagan Technologies Limited is a company registered in Northern Ireland
> with registration number NI 28773. The registered office of Lagan
> Technologies Limited is 209 Airport Road West, Belfast, Co. Antrim, BT3 9EZ.
>
> --
> http://www.freelists.org/webpage/oracle-l
>
>
>
>
> --
> J.A. van Zanen
>
>
>
> --
> Andrew W. Kerber
>
> 'If at first you dont succeed, dont take up skydiving.'
>
> The information in this message is confidential and may be legally
> privileged. It is intended solely for the addressee. Access to this message
> by anyone else is unauthorised. If you are not the intended recipient, any
> disclosure, copying, or distribution of the message, or any action or
> omission taken by you in reliance on it, is prohibited and may be unlawful.
> Please immediately contact the sender if you have received this message in
> error.
>
> The views and opinions expressed in this email may not reflect the views
> and opinions of any member of Lagan Technologies Limited, or any of its
> subsidiaries.
>
> Lagan Technologies Limited is a company registered in Northern Ireland
> with registration number NI 28773. The registered office of Lagan
> Technologies Limited is 209 Airport Road West, Belfast, Co. Antrim, BT3 9EZ.
>
>
>
>
> --
> Andrew W. Kerber
>
> 'If at first you dont succeed, dont take up skydiving.'
>
> ________________________________
> The information in this message is confidential and may be legally
> privileged. It is intended solely for the addressee. Access to this message
> by anyone else is unauthorised. If you are not the intended recipient, any
> disclosure, copying, or distribution of the message, or any action or
> omission taken by you in reliance on it, is prohibited and may be unlawful.
> Please immediately contact the sender if you have received this message in
> error.
>
> The views and opinions expressed in this email may not reflect the views
> and opinions of any member of Lagan Technologies Limited, or any of its
> subsidiaries.
>
> Lagan Technologies Limited is a company registered in Northern Ireland
> with registration number NI 28773. The registered office of Lagan
> Technologies Limited is 209 Airport Road West, Belfast, Co. Antrim, BT3 9EZ.
>
> --
> http://www.freelists.org/webpage/oracle-l
>
>
>

-- 
Niall Litchfield
Oracle DBA
http://www.orawin.info

--
http://www.freelists.org/webpage/oracle-l