John
Michael McMullen hit the point here, precisely.
>>We are seeing big problems when issuing disk writes using 10G
(both 10.1 and 10.2).
What tool did you use to see the write response time ? Did you trace
DBWR or LGWR to see the write response time and IO related waits ?
Assuming unix, does iostat indicates worse average response time for
those devices ?
>>The test is very simple and quick to do
And potentially misleading too. This test case is proving that
having very high commit frequency will introduce additional performance
issues.
** >> On 10G using local UFS disk the time various from 7:00 to 9:00
minutes and is very repeatable.
Is this code that you posted here takes this long ? What files are
in the UFS disk? Whole database or just log files?
**
If you want to understand why why your code is slower, turn on
SQLtrace in 9i and in 10g for your test case. Then find where that extra
time is spent. Also, compare session statistics between 9i and 10g. That
will tell you where to concentrate. Further, log file sync and log
buffer waits are not just IO related. You might want to decrease your
commit frequency to eliminate these events from the equation too.
There are so many different optimization techniques introduced in
10g, your test case might be probing the vulnerability of a feature.
Thanks Riyaj Shamsudeen ****
I understand that there is a severe difference in timings. But is it right to test fundamentally bad code? I've been testing 10g on a Sun T2000, both on the san and local disks. I never could get it as fast as my 8i/9i installations on other servers. Granted, I was not comparing apples and oranges. I had to give it back before I could bring 9i on the T2000 to test. But my initial reaction with 10g is it just didn't seem as forgiving as other versions of oracle. How about testing a big import with lots of parallel index creation? -- //www.freelists.org/webpage/oracle-l
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