Oracle Performance SS1000 w/ array

From: Roger Rowley <roger_rowley_at_mk.com>
Date: 1995/08/17
Message-ID: <410gqv$ab8_at_esgadm.esg.mk.com>#1/1


Hi all,

I am having some performance problems with my oracle system:

SUN SS1000 384MB Ram w/ SparcArray100 w/ 12GB Solaris 2.3 w/ Oracle 7.0.16.4 2 instances

The system is running Oracle financials 9.4.2 about 20-25 users.

We were getting poor performance with lots of swapping and paging, at the time we had 128MB .

Acording to Oracle with SQL*NET v1 we needed 6MB per user, so we were using all the memory in the machine.

We added 256 MB and increased the size of the SGA on each instance to 50MB . We still had poor performance. The increase in memory resulted in no increase in performance.

I looked at vmstat and iostat on the SUN and saw a large "page out" on vmstat (>300) . The system is running 25% waiting for IO .

However iostat reports throughput in excess of 15MB/sec and access times of <20Ms .

It seems the disks are performing OK, so why is the system still slow???

I checked the fragmentation rate using a formula from Oracle magazine, the lfi index. I get numbers on my main data tables around 15 !!! The article says to worry at 20 .

So the question is... Can fragmentation effect performance enough so SGA size becomes irrelevant ????

Roger Rowley
Systems Analyst
Morrison Knudsen Corp.
roger_rowley_at_mk.com Received on Thu Aug 17 1995 - 00:00:00 CEST

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