"Jonathan Lewis" <jonathan@jlcomp.demon.co.uk> wrote in message news:<brt18i$koq$1$8302bc10@news.demon.co.uk>...
> There are two possible waits with setting a
> tablespace into backup mode. The first
> is that it can't be done until all current
> transactions on the database have completed
> (although new ones can start).

Are you sure about this? It would be very difficult to make hot
backups if any long running transaction could block 'begin backup'.

I just tried in 8.1.7:
- in session1 started a transaction (deleted a record from a table)
- in session2 'alter tablespace begin backup' and it worked straight
away.

> --
> Regards
>
> Jonathan Lewis
> http://www.jlcomp.demon.co.uk

Regards,
Igor