On May 9, 5:59 pm, hopehope_123 <hopehope_..._at_yahoo.com> wrote:
> Hi ,
>
> I have a large datawarehouse system , running in archive log mode.
> Every night , an etl process runs and inserts/merges large amount of
> data. During the day no other updates are done.
>
> We take data backups by using rman everyday. If a failure occurs ,
> it is enough to return last nights backup. Since incremental data is
> in txt files, application can rerun the sqls.
>
> So , my question is : is it possible to restore the db successfully
> without making the tables which nologging dmls are run , unusable?
>
> Consider the following scenario:
>
> monday at 06:00 pm. level 0 data backup is done. it finished at 11:00
> pm.
> monday at 07:00 pm , i run : insert /*+append*/ into
> a_billion_rows_table select * from ten_rows_table; commit;
> this is completed at 10pm.
>
> tuesday db server crashed. i want to restore the db by using the
> monday level 0 backup. i dont care about the ten_rows insertion , i
> can rerun it because it is in txt files. is it possible to restore the
> db without making the whole billion_table unusable?
> does nologging insert statements running during the backup prevent
> this?
>
> if i restore the db , and recover , nologging operation is not
> recovered and the whole table becomes unusable just because of the 10
> records.
>
> i am thinking of a backup strategy :
>
> level 0 backup on mondays
> level 1 backup on other days.
>
> use nologging inserts/merges etc , without considering the backup
> times. ( when data backup is run , i also do nologging operations)
>
> if i need to restore the db , return to the one day before , open db
> with resetlogs , and miss only the last days update , without any
> table corruption ,
>
> does this work?
>
> Kind Regards,
> hope
It should.
Received on Wed May 09 2007 - 20:17:47 CDT
