wierd performance problem
Date: Thu, 10 Jul 2008 12:10:37 -0400
This only occurs with one table. The table is partitioned by day. It has about 160 gb.
I do the following:
where rownum < 2;
No indexes. Takes 30 seconds. Same thing on other tables the same size take 2 seconds.
I ran a 10046 trace and found that all my wait time is db file scattered
dug deeper. Looked at the raw trace file. I noticed I am doing ALOT of db file scattered read calls. My individual wait time on each call does not appear to be considerable.
why would I do so many scattered reads to just get the first record? I am having alot of performance problems with scanning this table and adding indexes.
Nothing else is going on. I am on a SAN.
As I said there is not any other activity.Received on Thu Jul 10 2008 - 11:10:37 CDT