At 10:27 AM 5/16/02 -0700, Chris Moll wrote:
Joseph Bishop wrote:
.........
Yes, we use 8K blocks. Has anyone run snoop to see if there is excessive calling to DNS for a lookup of the filer. That is something I saw recently.
We've seen aberant DNS behaviour certainly - the worst being misconfigured DHCP hanging mountd on the netapp. Looks ok now though.
I would not have DHCP on an NFS machine. Only fixed IP.
Is the Network dedicated to the NetApp? Are you on Gigabit Ethernet?
yes (100Mbit), no (about to switch to gigE)
That will bump your database performance by 100-200%
Also, I think that 8.1.7 is better on Solaris 2.8.
interesting, the newest machines are 2.8 but at the moment the main workhorses are still 2.6.
Latest developments: after various efforts at tuning the DBs, it now appears that for most jobs the performance difference has been more than made up for. In fact one big job runs somewhat faster on the netapp than on local disk... There was one remaining pathalogical job, but just today one of the programmers discovered an SQL change dramatically sped the job up.
So in summary: it appears to me that oracle 8.1.7 has changes to it that may cause worse performance for poorly configured DBs compared to oracle 8.0.5, especially on the netapp. A bit of standard Oracle tuning wipes out the difference and brings the netapp back much closer to local disk performance (with 100MBit). But in certain cases SQL changes were the cure (always a waste tweaking performance parameters when the application is doing something grossly inefficient...)
Yep, SQL can be a hog. I had a query once that ran for over a minute. Problem was our application needed it to complete in less than 2 seconds. After reworking the query into a stored procedure with 2 queries, we got to .3 seconds.
Chris Moll Lawrence Berkeley Laboratory
Nice chatting with you. Any help I can give ....you can have.
Joe