From: darryl snedeker Subject: Re: HELP: Info about ORACLE7 Performance on RAID Date: 1995/08/08 Message-ID: #1/1 sender: news@txnews.amd.com references: <3vqpac$9rp@maverick.tad.eds.com> <406gd8$sui@data.interserv.net> to: Will content-type: text/plain; charset=us-ascii organization: Advanced Micro Devices mime-version: 1.0 newsgroups: comp.databases.oracle x-mailer: Mozilla 1.1N (Windows; I; 16bit) Will Kooiman, kooiman@interserv.com wrote: >> Peter Constantinou writes: >> X-URL: news:comp.periphs.scsi >> Content-Transfer-Encoding: 7bit >> Content-Type: text/plain; charset=us-ascii >> >> Does any one have experience of ORACLE7 applications running on RAID disk >> arrays. I have been told that performance is poor for Oracle V6 applications, >> but cannot find anyone with experience of ORACLE7. >> >> FYI The application is ORACLE7 v7.0 running on IBM RS/6000 under AIX 3.2.5 >> (soon to be ORACLE7 v7.1 under AIX v4.0). We are looking to purchase 12Gb of >> Seagate or IBM based RAID (configured for RAID level 5). >> >> Thanks in advance for any info >> >> Peter C >> >> -- >> rosepete@xs4all.nl Phone: +31 10 4987 727 Fax: +31 10 2120 295 >> EDS BV, Electronic Data Systems, The Netherlands. >> >> >>>>> > >I've used RAID 0,1,0+1, and 5 with Oracle 6 and 7, and saw no difference in >performance between the two. > >I didn't see a lot of improvement in TP oriented access, but I saw a big >improvement in decision support queries (table scans). > >I'm not a big fan of RAID 5 due to it's VERY poor write performance. If you think it's >bad when all the disk drives are working, wait until a drive fails. You still have your >array, but the system seems to halt due to poor performance. > >My absolute favorite is RAID 0+1. This gives you redundancy, with unbelievable >performance. But, it costs a lot since you must buy twice as many disk drives as >you would have to otherwise. > >Quick RAID overview: > >Without going into a lot of detail, here's the scoop on the most popular RAID levels. > >RAID 0 (mirroring) reads are slightly faster, writes are slightly slower (with redundancy) >RAID 1 (striping) reads are much faster, writes are much faster (no redundancy) >RAID 0+1 reads are much faster, writes are much faster, (with redundancy) >RAID 5 reads are much faster, writes are much slower (with redundancy) > > >Hope this helps, >Will Kooiman > > Will, Thanks for the reply. Is very helpful. -D