Re[2]: Auto Stats Job

Hello Chris,

Interesting way how you distribute the workload on 4 nodes dynamically (i guess) after 1/4 objects as per stale statistics objects , can i request you to please Share the way you how it's done.

Thanks & Regards,
orion
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Thursday, 09 August 2018, 09:50p.m. +05:30 from Chris Taylor christopherdtaylor1994_at_gmail.com<mailto:christopherdtaylor1994_at_gmail.com>:

While that's technically TRUE, Oracle also (in the same paper maybe?) says some databases may better to create your own methodology based on your workload. They equally support doing either.

I've almost always rolled my own stats routines based on the system in focus. (For non-critical systems - for systems that 'just run' I just leave the automated jobs on and let them do the work). But for busy, busy critical systems, it almost always makes more sense to roll your own .

For instance on a 4-RAC node I rolled out a script that would do the work and determine the objects with stale stats, then divide those objects by 4 and run the stats job across all 4 nodes and divide the tables up so that each node did 1/4 of the tables needing new stats. Also get rid of histograms almost always until you know you need histograms on a specific table+column.

Chris

On Thu, Aug 9, 2018 at 11:02 AM Q A I S E R <qrasheed_at_gmail.com<mailto:qrasheed_at_gmail.com>> wrote:

Hi Sanjay,

The preferred method for gathering statistics in Oracle is to use the supplied automatic statistics gathering job. You could tune the automated job so it completes succesfully. You could use parallelisim, change stale percentage, use concurrent stats by setting Gather Optimizer Statistics Default Options. You can also increase the maintenance window time, so the job completes.

Following white papaer on "Best Practices for Gathering Optimizer Statistics" may help. Please see section 'Improving the efficiency of gathering statistics'

https://www.oracle.com/technetwork/database/bi-datawarehousing/twp-bp-optimizer-stats-04042012-1577139.pdf

Thank,
--Qaiser

On Wed, Aug 8, 2018 at 4:15 PM, Sanjay Mishra <dmarc-noreply_at_freelists.org<mailto:dmarc-noreply_at_freelists.org>> wrote: Hi Experts

I had question on Auto Stats job in 12c which is running for 4hr now from 10pm to 2am. I had multiple heavy used environment where lost of objects shows up for stale stats and the job failed to finish in 4 hr and so multiple critical table stats were not collected. If I am running the job as manually then can have more degree and can finish the job in less than 4 hr. So how Oracle allocated Degree when Degree defined for all database objects is 1 and what can be done to update like preference or so to complete the auto job in time. Don;t want to add layer by using cron

Rgds
Sanjay

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http://www.freelists.org/webpage/oracle-l Received on Fri Aug 10 2018 - 21:26:35 CEST