Re: Newbie ?: Rollback Segments and the High Water Mark

From: Verna Legaspi <vlegaspi_at_uswest.net>
Date: Sun, 3 Oct 1999 10:38:48 -0700
Message-ID: <MuMJ3.3881$Wy2.184336@news.uswest.net>

Sybrand Bakker <postbus_at_sybrandb.demon.nl> wrote in message news:37f73fed.28454963_at_news.demon.nl...

> A larger transaction will force Oracle to allocate extra extents in
> the rollback segment. This increases the HWM. Unless you set OPTIMAL
> for each rollback segment (which I personally never do), once the
> transaction has been committed, the space will not be deallocated, it
> is however 'free' to be used by another transaction.

So... even though the space in the RBS has not been deallocated, it is still "free" to be used by another transaction? I guess my main concern is -- when, then, should I worry about my RBSs if the HWM is not my "red flag?"

> If you set OPTIMAL Oracle will trim down the rollback segment. However
> later on it probably is extended again. That's something I want to
> avoid in my systems

Why would you want to avoid this activity? Is it a performance issue?

Thank you for your responses. I am switching between newsgroups and reading my "Oracle 8 DBA Handbook." Received on Sun Oct 03 1999 - 12:38:48 CDT