RE: performance issue for a specific column selection
- From: <amit.sharma@xxxxxxxxxxxxx>
- To: <oracle-l@xxxxxxxxxxxxx>
- Date: Wed, 28 Sep 2005 11:43:06 +0100
Is there an index on hospital_id column, how big is the table?
Regards
Amit
-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]On
Behalf Of raja rao
Sent: 28 September 2005 11:37
To: oracle list
Subject: performance issue for a specific column selection
Hi All,
Can someone help me why a simple select is behaving strage:
select hospital_id,acct# from HSTAB where rownum=1;
This is almost taking 20 seconds to get the data. Where as teh same sql
without hospital_id column is taking just less than a second.
select acct#,mr# ,admit_dt from ...
This is taking less than a second. The only problem is with the hospital_id
column.
When I checked the wait events, the below are the waits:
SID EVENT MODULE
----- ------------------------------ -----------------------------------
USERNAME P1 P2 P3
---------- ---------- ---------- ----------
73 direct path write SQL*Plus
OPS$ORACLE 201 6365 7
my db_files param is 200. So this file is temp file the wait is happening on.
I already have DISK_ASYNCH_IO=TRUE .
What else i have to do to fix this issue.
Thanks in advance,
Raj
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