Re: stripe redo logs

Hi,

we have striped redos and no problems, but no benchmarks. In an OLTP-DB , where takes place most time only selects I can't see any problems.

"John D. Parker" wrote:
>
> thanks for the manual reference. Have you actually tried this or benchmarked
> this? We all have our own opinions, but I am trying to find actual experiences
> or benchmarks.
>
> John D Parker
>
> Torsten Borchert wrote:
>
> > Hi,
> >
> > you can stripe online redologs too for better performance. I've found it
> > in Oracle8 Tuning, Chapter 15 Tuning I/O, Tuning LGWR I/O:
> >
> > "
> >
> > Applications with a lot of INSERTs, or with LONG/RAW activity may
> > benefit from tuning LGWR I/O. The size of each I/O
> > write depends on the size of the log buffer, which is set by the
> > initialization parameter LOG_BUFFER. It is thus important to
> > choose the right log buffer size. LGWR starts writing if the buffer is
> > one third full, or when it is posted by a foreground process
> > such as a COMMIT. Too large a log buffer size might delay the writes.
> > Too small a log buffer might also be inefficient,
> > resulting in frequent, small I/Os.
> >
> > If the average size of the I/O becomes quite large, the log file could
> > become a bottleneck. To avoid this problem, you can
> > stripe the redo log files, going in parallel to several disks. You must
> > use an operating system striping tool, because manual
> > striping is not possible in this situation. "
> >
> > Torsten
> >
> > "John D. Parker" wrote:
> > >
> > > What are the feelings about striping redo logs? It appears that the
> > > "Oracle8 and Unix Performance Tuning" by Alomari does not think this is
> > > a bad idea. Also, "Oracle8 Data Warehousing" by Dodge and Gorman does
> > > not think this is a bad idea. I myself have very mixed feelings about
> > > this since redo is sequential write by one and only one process.
> > >
> > > What are the opinions of this newsgroup? Does anyone have any experience
> > > or actual benchmarks of this?
> > >
> > > To Stripe Redo or not Stripe Redo
> > >
> > > --
> > >
> > > John D Parker
> > > Sr ORACLE DBA
> > > SABRE Technology Solutions
> > > ofc: 918-828-6025
> > > fax: 918-828-6096
> > > john_parker_at_sabre.com
>
> --
>
> John D Parker
> Sr ORACLE DBA
> SABRE Technology Solutions
> ofc: 918-828-6025
> fax: 918-828-6096
> john_parker_at_sabre.com
Received on Mon May 17 1999 - 07:23:51 CDT