In Oracle 7.3.4, between ALTER TABLESPACE ... BEGIN BACKUP and ALTER
TABLESPACE ... END BACKUP, does DBWR write to the tablespace datafiles? If
it does, do you have a not-too-long explanation of how this is handled at
recovery? I mean, Oracle can't possibly know which datafiles/parts of a
datafile that I have already copied, can it?

The v$backup view reports the backup status of datafiles. Am I right in
saying that all datafiles belonging to the same tablespace must have the
same status? If so, why does the v$backup view report per datafile, and not
per tablespace?

Does the control file contain information about backup status (in
particular, the time of backup) of datafiles/tablespaces? If so, should I
also backup the control file after partial backups?

Can I delete archived log files after successful online backup of all
tablespaces? If so, I guess that the most recent achived log file that I may
delete, is the file with sequence number 1 less than oldest online log
sequence number before I start the first partial backup?

Grateful for any help.
 

Regards,

Roy Brokvam
[email protected]

>In Oracle 7.3.4, between ALTER TABLESPACE ... BEGIN BACKUP and ALTER
>TABLESPACE ... END BACKUP, does DBWR write to the tablespace datafiles?

AFAIK, data blocks are not written to datafiles but the only possibility
of changing datafiles is slightly updating their headers by backgrounds.

>The v$backup view reports the backup status of datafiles. Am I right in
>saying that all datafiles belonging to the same tablespace must have the
>same status?

Not exactly.

>If so, why does the v$backup view report per datafile, and not
>per tablespace?

State of datafile may be changed by ALTER DATABASE DATAFILE '/x/y/z'
END BACKUP. This eliminates the need to perform media recovery in case
of instance crash during hot backup, for example.

>Does the control file contain information about backup status (in
>particular, the time of backup) of datafiles/tablespaces?

Control files operates at physical level, so they don't know tablespaces.
That's why v$backup operates with datafiles, not tablespaces and it is
available justa after mounting the database.
They hold info about datafiles. AFAIK controlfile contains info about
checkpoint, stop /etc SCNs performed against datafiles, but hot backup
info is held only in datafiles headers.

>If so, should I also backup the control file after partial backups?

Backup them. But primarly for that they might be needed during
incomplete recovery.
Also back up controlfiles immediately after changing physical structure
of database, adding/dropping datafiles, redo groups/members for example.

>Can I delete archived log files after successful online backup of all
>tablespaces?
>If so, I guess that the most recent achived log file that I may
>delete, is the file with sequence number 1 less than oldest online log
>sequence number before I start the first partial backup?
 

Yes, you still need redo that was current one during bringing
first tablespace into backup mode.
But if it is not a very big problem, better compress & archive them
on tape and/or juke boxes as some elder backups.

--
Piotr Kolodziej [email protected]
Just my private opinion.