Hi,

I'm not familiar with DB/2 but I think the main difference
between online backup of DB/2 and online backup of SAP R/3
using TDP is that TDP backs up *ALL* data you would need to
restore SAP R/3 in one go. This backup includes database, archive logs
and some flat files.
With an online DB/2 backup you only get the database.

Another advantage of TDP is that you are using a SAP certified
way to backup the system (there might be other).
Furthermore you can check the SAP backup within SAP (transaction DB12).

We are running SAP R/3 with Oracle on W2K so your mileage might vary.

Kind regards
Thomas Rupp
Vorarlberger Illwerke AG