Prod patching taking v long time compared to Non Prod

Issue: In Prod, Patching taking v long time compared to Non Prod.

          Checked the system load and all. All are normal. Still we are facing performance issue.

Sol : After doing lot of R & D we got one reason y this might be happening in PROD.

In PROD:

SQL> select count(*) from dba_tables where last_analyzed < sysdate-30;

COUNT(*)

----------

20000

In Non PROD:

SQL> select count(*) from dba_tables where last_analyzed < sysdate-30;

COUNT(*)

----------

500

--- there are many tables with statistic older than 30 days on PROD.

--- We thought of running GSS in parallel to patching ( In our cases we had still around

     20hrs more work of patching. So, it worth running GSS since there is a long work to complete )

--- Since running GSS will also take long time nd consume lot of resources, better run

     GSS for identified Shemas for which you are about to patch next

--- In our case we are about to proceed with HRMS patching.. So we ran GSS for HR

     and AR modules and proceeded with patching.

   

     as SYS

     exec dbms_stats.gather_schema_stats(ownname=> 'HR' , estimate_percent=> 25 ,degree=>8);

     exec dbms_stats.gather_schema_stats(ownname=> 'AR' , estimate_percent=> 25 ,degree=>8);

           

Also.. It will be much helpful..if U too can update on perfomance issues which U faced while patching.

This will help a lot bec...most of the times we will fall short of downtime.. in tht cases we can have some options to go for...

Thanks,

K K K...Kiran :-)