Retention Guarentee on Standby Database

Question

Hi
i am facing frequent Ora-01555 on my 11.1.0.7 standby database used for reporting.
I increased UNDO_RETENTION=50000
I increased UNOD tablespace size to 40Gb
I checked the usage of UNDO tablespace its 99% free
UNDO_MANAGEMENT is AUTO
Again the ora-01555 comes up.
I wanted to enable retention guarentee on my Standby database :
I did : alter tablespace UNDOTBS retention guarantee; got an error stating database open for read access only
I did : alter tablespace UNDOTBS retention guarantee; on primary and switched log , checked that log applied .
Log applied on Standby , but still when i do :
select retention ,tablespace_name
from dba_tablespaces where tablespace_name like 'UNDOTBS';
NOGUARENTEE is the value .
but GUARENTEE in Primary
Please , how can i do this ?
Thanks

Answer 1

My point was that since your Standby is Read Only, there are no writes to Undo -- you can't set RETENTION GUARANTEE.
So it would seem that, at the point in time when you OPEN READ ONLY, many of the Undo Extents have already been expired -- from the Primary.
OR your ORA-1555s are resulting from some other issues -- eg the Transaction Slot in the Undo Segment Header has already been overwritten --- from the Primary.
At what point in time, relative to the transaction activity, do you OPEN READ ONLY ? Can you open the database at some other (earlier) time ?
Hemant K Chitale