Saturday, May 19, 2012

Awr settings after resetlogs what happens to them



Last week i had to investigate a perf issue on the ACCEPTANCE environment which is a restore of the production database, I had to compare the awr reports of a monthly job.

On production I've set a retention of 40 days in order to be able to debug issues with a monthly job and to have some buffer.


We restore ACCEPTANCE from PRODUCTION backups and the change dbname and dbid with nid (for some reason aka bug we are not able to duplicate the db with rman)


as you can see from the sql hereunder the retentention is different for the PROD db (dbid 2789041670)
as for it's cloned brother ACC (1857427655)


select * from DBA_HIST_WR_CONTROL;




DBID              SNAP_INTERVAL RETENTION      TOPNSQL
--------             --------------------------        -------------------      ---------------
2789041670 0 0:20:0.0                           40 0:0:0.0            DEFAULT
1857427655 0 1:0:0.0                             7 0:0:0.0               DEFAULT


so AWR reset to the defaults after using nid and opening with resetlogs.

adapt your procedures to change the retention again after a clone ... 

Tuesday, May 8, 2012

ulimit and prctl ....

while installing rac in zones we had a strange issue
when we tried to install the db with an sga > 4gb it gave a nice

ORA-27102
out of memory execption

we checked the project parameter and everything seemed ok....

execpt of the process.max-address-space
for some strange reason it was on 4Gb no mather to what we put it .....

STRANGE

after lots of investigation it seemed that  ulimit -v was called from a .bash_profile which limited the shell to 4Gb

once removed everything worked fine .....