Re: Rollback segments

From: Alexandre Leite <aleite_at_sysdesign.com.br>
Date: Thu, 25 Mar 1999 16:15:18 -0300
Message-ID: <7de1s0$b7$1@srv4-poa.nutecnet.com.br>

Jean,

For OLTP applications is best to have many small rollback segments, one to four
per concurrent session. For batch jobs and DSS applications is best to have a few
big rollback segments. Small rollback segments can be cached in memory.

You can associate a transaction to a specific rollback segment such as small transactions use small rollback segments and big transactions use big rollback
segments.
Use the command:
SET TRANSACTION USE ROLLBACK SEGMENT <rollback segment name>.

Rollback segments aren't automatically online because they could be used for some instances which access the same database (Oracle Parallel Server Option with public rollback segments).

Alexandre Leite.
Oracle Certified Professional
leite_alexandre_at_hotmail.com

Jean-François Vincent escreveu na mensagem <36FA6214.3BF41116_at_platinum.com>...
>Is it best to have one big roollback segments or
>a few small ones ?
>
>why all the rollbacks segments are not automatically online at the
>startup, i know how to change that but i don"t know why.
>
>thank you for explanation.
>
>J-Fr.
>
Received on Thu Mar 25 1999 - 13:15:18 CST