database crash is nonsense, the system stays avaliable. Sorry
--
bye ali
ali beidoun wrote:
> 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 Wed Apr 08 1998 - 00:00:00 CDT
