> As noted, one of the main problems is knowing where to begin
> in the log. This can be handled by having backup processing
> update the control file with the first lsn and log file
> required. At the time of the backup, this information is or
> can be made available. The control file can be the last file
> added to the tar and can contain information spanning the entire
> backup process.
lsn and logfile number (of latest checkpoints) is already in the control
file, thus you need control file at start of backup. (To reduce the number
of logs needed for restore of an online backup you could force a checkpoint
before starting file backup)
You will also need lsn and logfile number after file backup, to know how much
log needs to at least be replayed to regain a consistent state.
Andreas