RE: Questionable V$SQLAREA Statistics

From: Khedr, Waleed <Waleed.Khedr_at_FMR.COM>
Date: Mon, 01 Jul 2002 13:08:25 -0800
Message-ID: <F001.0048D431.20020701130825@fatcity.com>

What is the degree of parallelism on this table?

Waleed

-----Original Message-----
Sent: Monday, July 01, 2002 4:39 PM
To: Multiple recipients of list ORACLE-L

Here's the scene:

1. I have a 400,000 row table table which is cached.
2. I have a query against that table and no other with one column referenced in the WHERE clause. (This column is indexed and of course I don't really need the index since the table is cached but it's there so ho hum...)
3. When I run tkprof on the query it shows a full table scan ignoring the index... that's what I want 'cause it's cached.
4. But when I look at V$SQLAREA the DISK_READS column is incremented.
5. This query is executed very often so my StatsPack report lists it as one of the most expensive queries in terms of physical reads.

It appears that Oracle is counting full table scans of cached tables as DISK_READS in V$SQLAREA. Seems like this is a bug to me 'cause it's not really a physical disk read but is getting data from the buffers.

Don't you think this is a bug? Has anyone seen this before?

Steve Orr
Looking for cache in Bozeman, Montana
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Author: Orr, Steve
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Author: Khedr, Waleed
  INET: Waleed.Khedr_at_FMR.COM

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To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). Received on Mon Jul 01 2002 - 16:08:25 CDT