Re: stripe redo logs

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
Received on Fri May 14 1999 - 06:57:57 CDT