Hi Managers :
Thank you to all who replied :
Taylor, Shirley I [TaylorS_at_mar.dfo-mpo.gc.ca]
matthias.reiter_at_de.pwcglobal.com
Mullin, Stephen (CAP, ITS, US) [Stephen.Mullin_at_gecits.ge.com]
****************************************************************************
*********************************************************
My original post was :
These are the results of the NSR/SAP interface (with Oracle):
The first operation that brbackup does is the SQL sentence "Alter
tablespace XXX begin backup", for all tablespaces defined in the
data base.
Then it calls backint (which sends the data). Once backint finishes
its
operation, the tablespaces return to normal operation, through the
sentence
"Alter tablespaces XXX end backup".
The secuence forces ALL tablespaces to turn on BACKUP mode, freezing
the
updating of data base during backup execution. This is not the way
that
Oracle works, because it recommends to use only one tablespace on
BACKUP
mode, then back it up and turn off its BACKUP mode. After that, go
on with
the following one.
The query is :
Is it possible to use NSR in the way that Oracle works ????.
****************************************************************************
*********************************************************
Matthias Reiter wrote :
Oracle does not freeze writing to the tablespaces. Oracle just stops
updating the checkpoint number in the tablespace files.
Oracle will continue to write modified blocks to the
tablespace files while in backup. What every backup-tools
puts on tape is all unmodified blocks plus old or new content of
modified blocks.
On recovery oracle will overwrite all modified blocks with the
content of the archived and online redologs.
So what brbackup does is ok. If you do not use software
compression, a backup while full production is no problem.
Oracle is designed to run permanently !
Oracle 7 Server Concepts Manual, 1992,
Chapter 24 Database Backup, page 24-4:
... can be backed up while ... open, while ... online ...
and in normal use.
An online .. backup ... fuzzy data.
... alter ... begin backup ...oracle stops recording the
occurrence of checkpoints ...
Cristian Ramirez Villarroel
Gerencia de Software
SONDA S.A.
FONO : ( 56 2 ) 6962277
FAX : ( 56 2 ) 2471031
email : cristian.ramirez_at_sonda.cl
Received on Thu Dec 17 1998 - 13:56:58 NZDT