Re: optimal size for rollback

"Richard Foote" <richard.foote_at_bigpond.com> wrote in message news:q9jj9.37911$g9.108570_at_newsfeeds.bigpond.com...
> Hi Howard and Karen,

> One last point. Note that automatic undo management does extra work 'under
> the covers' which could be viewed as being sub-optimal. I haven't heard
many
> that suggest using manual rollback segments is the way to go in 9i ...

Connor certainly suggested that automatic undo management was

'basically an OPTIMAL clause
just under the covers...Its like "Oops, I'm an extent thats 3 seconds over the retention limit...bang, I'm outta here"'

which isn't exactly a ringing endorsement...

And I must admit I am still sitting on the fence, at least partly because I don't really understand what AUM is actually doing, and partly because sufficient equisized public rollback segments have never done me any significant harm. Sizing them wrong or leaving a big or small rbs segment online when I didn't intend to on the other hand.

--
Niall Litchfield
Oracle DBA
Audit Commission UK
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