Are offline backups an option, or a neccessity?

We are about to implement SAP over Oracle with a 24*7 requirement. I am advised by the basis consultant of the implementation partner that we should be taking the RDBMS offline at least once a week for an offline backup, *or*, we need three times the amount of disk to carry out some kind of complicated rolling type backup. This is in spite of the Oracle RDBMS supporting an online backup mode, which we are advised to carry out nightly.

Is it really neccessary to take the system offline regularly to do a backup? Can the online backups alone be relied on for a robust solution?

I need to get my head around the issues here as the consultant said 'the RDBMS supports an Online backup no problem' then in the next breath is advising to take the system down regularly, or triple our disk budget.

We would rather not do either if we can reliably not do so.

your advice is appreciated.

TIA
rgds

Peter Tashkoff <tashkop_at_iname.com>
Zespri International Limited Std Disclaimers Apply All rights reserved. No party may use this document to vilify another.

Zespri New Zealand Kiwifruit, The World's Finest

-------------------==== Posted via Deja News ====-----------------------
      http://www.dejanews.com/     Search, Read, Post to Usenet