RE: What happens during open resetlogs?

  • From: Tanel Poder <tanel.poder.003@xxxxxxx>
  • To: alever@xxxxxxxxx, "'oracle'" <oracle@xxxxxxxxxxxxx>
  • Date: Tue, 22 Aug 2006 22:12:19 +0800

The most important task of a resetlogs operation is updating the
RESETLOGS_CHANGE# in datafile headers (as seen from V$DATAFILE_HEADER).

All other things like overwriting online redologs and updating controlfiles
are secondary, not crucial (you don't even need online redologs in order to
roll forward an old backup using archivelogs to some point in past. Also,
the need for controlfiles is just for convenience, not crucial for

Updating resetlogs_change# states that these datafiles belong to a new
incarnation of the database now and any more archivelogs generated by the
"old" database can't be applied to this new incarnation (with one minor
exception of recovering over resetlogs though).

Btw, Oracle 10g includes the resetlogs_change# in the default
log_archive_format string now as well, so nobody would accidentially try to
apply wrong logs (although with similar log sequence numbers) to their


> -----Original Message-----
> From: oracle-l-bounce@xxxxxxxxxxxxx 
> [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of 
> Alessandro Vercelli
> Sent: Tuesday, August 22, 2006 18:04
> To: oracle
> Cc: oracle-l
> Subject: Re:What happens during open resetlogs?
> Maybe you can find a brief answer on an old 8.16 release 
> Oracle Doc. Part No. a76993.
> Good luck for you exam,
> Alessandro 


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