Subject Re: [firebird-support] NBackup level 0 vs. file copy?
Author Konstantin Khomoutov
On Tue, 8 Oct 2013 12:37:57 +0200
Kjell Rilbe <kjell.rilbe@...> wrote:

> Working with FB 2.5 on Windows 64 bit, how does Nbackup level 0
> perform compared to a high-performance copy utility like FastCopy?
>
> I'm asking because my DB is 80+ Gbyte and both the database and the
> backup are currently on the same physical disk. FastCopy works with
> large chunks to minimize time wasted on disk seeks.
>
> How does NBackup perform in this regard?
>
> Second question: after transferring the level 0 backup file to a
> secure backup volume, I want to use it to create a DB copy for
> test/delev/debug purposes. I can do that using Nbackup restore, b ut
> does this imply copying the entire database yet again?
>
> With a file copy solution with Nbackup lock, I can essentially use
> the copy "as is" (need to do Nbackup fixup + sweep though). I.e. a
> single read+write of 80 Gbyte. Is this possible with a Nbackup level
> 0 backup approach?

Note that nbackup not only copies the data but also updates a special
system table in the database, recording the backup level, timestap and
name of the destination file. This is used by nbackup to create backup
of the next (lower level). So if you intend to ever take backups of
lower levels, I'd say you have to use nbackup to do the job, otherwise
lock/copy/unlock is a quite reasonable alternative, I reckon.