Thanks for detailed FUZZY explanation Tanel. Eh... mean explanation of
FUZZY. :-)
Yep. We can trun it other way around depending what is more
convenient. :) Oracle is permanently recovering its datafiles - during
recovery redo records are taken from archived/redo logs, physical
standby gets redo records from transfered archive logs, normal
database gets redo records from SGA/PGA.
2006/6/10, Tanel Poder <tanel.poder.003_at_mail.ee>:
> Btw, have you ever have been wondering, how Oracle can have predictable
> results from recovery given the huge complexity of redo records and room for
> error (e.g. when restoring a year old backup and applying all archivelogs
> will eventually result in 100% identical database with current one)?
>
> The key is that Oracle actually uses exactly the same kernel functions for
> recovery and making changes to data blocks. E.g. if we do DML, we are just
> going to prepare redo records in either PGA or public redo strands in shared
> pool and then the recovery function will apply the redo records do buffers
> in buffer cache, making whatever changes are needed, just as with normal
> recovery.
>
> This means that watch out when having different binaries / patch levels for
> your standby databases..
--
Best regards,
Alex Gorbachev
http://oracloid.blogspot.com
--
http://www.freelists.org/webpage/oracle-l
Received on Sat Jun 10 2006 - 03:25:24 CDT
