Re: Re: Query ASH for Undo Blocks

Hi Guys,
thanks for your help. I was ill yesterday, therefore the late reply. Currently I do not have the priviledges to run a trace. Let us see how long it takes to get them. _at_Jonathan I send some evidence ASAP.
Thanks
Lothar
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Von : jlewisoracle_at_gmail.com
Datum : 15/06/2022 - 09:32 (MS)
An : oracle-l_at_freelists.org
Betreff : Re: Query ASH for Undo Blocks         

  Stefan,           

  Following some of the examples of the newer trace mechanism that you and Tanel have published - can you think up a specification for tracing that would allow the process stats to be dumped to trace for a given SQL_ID at the start of call and end of fetch? I think there's a PROCSTAT call from oradebug, but would have to do some research to see if I could get the effect from "set events".           

  Regards    

  Jonathan Lewis                  

  On Mon, 13 Jun 2022 at 13:22, Stefan Koehler <   contact_at_soocs.de> wrote:       

  Hello Lothar,   

 you can trace logical I/Os (events 10200 and 10201) or use already available OS tracing scripts for that, e.g. ...      

• SystemTap: https://db-blog.web.cern.ch/blog/luca-canali/2014-12-life-oracle-io-tracing-logical-and-physical-io-systemtap
• DTrace: https://alexanderanokhin.wordpress.com/2011/11/13/dynamic-tracing-of-oracle-logical-io/)

 ... for the latter you need to use
  web.archive.org.      

 Best Regards   

 Stefan Koehler      

 Independent Oracle performance consultant and researcher   

 Website:
  http://www.soocs.de   

 Twitter: _at_OracleSK      

> Lothar Flatz <

  l.flatz_at_bluewin.ch> hat am 13.06.2022 14:04 geschrieben:   

>
  

> Hi Guys,
  

>
  

> thanks a lot Lok, Mohamed and Nenad. Unfortunately that index is almost all cached.
  

> Thus I have only 2 physical read both from undo....
  

> I can see some evidence that we have a undo issue, but can not proof it.
  

>
  

> Thanks
  

>
  

> Lothar
  

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