Another problem you will get when a database or system crash happens.
The data stored in the RAM drive will be lost, but oracle needs this for
its intance recovery to rollback uncommited transactions.
--
bye ali
Jerry Gitomer wrote:
> Hi Femi,
>
> Given that Oracle keeps everything in the SGA why do you want to use
> your own RAM drive? I suspect that doing so can cause memory contention
> problems. In fact one of the cautions in the various books on Oracle
> tuning is not to make your SGA so big that the operating system will
> swap out part of the Oracle SGA. By creating a RAM drive you are, in
> effect, making an assumption that you can manage memory better than
> Oracle does. creating an oversized SGA.
>
> When you say the rollback segment keeps blowing up I assume that you
> mean it is out of space. There are entire chapters about managing
> rollback segments. The quick and dirty solutions are:
>
> 1. Increase the size of the rollback segment
> 2. Assign the transaction to a specific rollback segment large enough
> to handle it.
> 3. Increase the frequency of your commits so that less data need be
> stored in the rollback segment.
> 4. Examine your select statements to see if you can eliminate
> redundant order by clauses etc.
>
> Unless you are running batch updates or loads of large tables the
> contents of a rollback segment should be well under 10 minutes old. In
> fact, in a typical OLTP environment it should be rare to have data in
> rollback segment that is much more than a minute or two old.
>
> Regards
>
> Jerry
>
> Femi Aderounmu wrote:
> >
> > Does anyone have experience with RAM drive based databases. I am new to
> > Oracle and I am trying to create a database with the data and rollback
> > files located in RAM drives.
> >
> > I create a RAM drive, then use a SQL code file to automatically load
> > datafiles on my hard drive into the RAM drive. The main problem I have
> > encountered:
> >
> > 1)The Rollback segment keeps blowing up. How can I safely delete it or
> > reduce it's size during operation?
> >
> > I understand that the rollback file should be kept on the hard drive but
> > I care little for old data. The data becomes useless after about 10
> > minutes anyway, since the application is a semi-real time application.
> >
> > --
> > Femi
> > New Jersey
> > --
>
> --
> Jerry Gitomer ICT Group
> jgitomer_at_ictgroup.com Langhorne PA
> jgitomer_at_p3.net Opinions are mine not those of ICT Group
Received on Tue Apr 07 1998 - 00:00:00 CDT
