Re: most expeditious way to update a large number of rows

From: hpuxrac <johnbhurley_at_sbcglobal.net>
Date: 16 Oct 2006 16:02:27 -0700
Message-ID: <1161039747.815968.220650@h48g2000cwc.googlegroups.com>

myl..._at_gmail.com wrote:
> > Thanks, Brian. That was extremely helpful. The result of your query
> > is 736. I assume that's bytes, right?
> >
> > If that's the case, my update will generate ~ 471MB of redo.
> >
> > Thanks again,
> > Myles
>
> Sorry, that's "736" after updating a single row.

Don't take too much faith in the number for an update of 1 row. If you take a larger sample ( 1000 rows maybe ) that should give a good guesstimating tool.

As others have noted, Tom Kyte has a lot to say in this area and his books are well recommended as well as his website http://asktom.oracle.com ... if you use the website and do a search on say "estimate redo" you will probably get some good info. Received on Mon Oct 16 2006 - 18:02:27 CDT