Re: Can I tryst in "physical ... direct" figures?
- From: "Jonathan Lewis" <jonathan@xxxxxxxxxxxxxxxxxx>
- To: <oracle-l@xxxxxxxxxxxxx>
- Date: Fri, 24 Sep 2004 07:01:07 +0100
As Terry points out, there could be a lot of sorting
going on. Your figure would not be unreasonable
(for example) in a data warehouse that was doing
lots of 'Create table as select'/'report table'.
To increase confidence - you could cross-check these
figures against the tablespace I/O figures. Direct writes
are usually multiblock writes. Direct reads are usually
multiblock reads - the tablespace (and file) stats will
give you a further indication of what proportion of
your reads and writes were direct.
Regards
Jonathan Lewis
http://www.jlcomp.demon.co.uk/faq/ind_faq.html
The Co-operative Oracle Users' FAQ
http://www.jlcomp.demon.co.uk/seminar.html
Optimising Oracle Seminar - schedule updated Sept 19th
----- Original Message -----
From: <J.Velikanovs@xxxxxxxx>
To: <oracle-l@xxxxxxxxxxxxx>
Sent: Thursday, September 23, 2004 11:09 PM
Subject: Can I tryst in "physical ... direct" figures?
9.2.0.5 EE on Lintel RH AS 2.1
OLTP ~200 connections.
Today a have observed figures below in statspack report
Statistic Total per Second per
Trans
--------------------------------- ------------------ --------------
------------
physical reads 19,327,036 429.5 205.8
physical reads direct 10,482,393 232.9 111.6
physical writes 16,465,203 365.9 175.3
physical writes direct 16,343,723 363.2 174.0
It seams very strange to me that almost all writes and more then 1/2 of
reads is direct.
What do you think, can I trust on those figures? Can it be truth that all
writes are direct "bypassing the buffer cache, as written in Docs?
PS Report interval 750.02 (mins)
PS I know - SP aggregates live. Don't tell me do not look on it.
Jurijs
+371 9268222 (+2 GMT)
============================================
Thank you for teaching me.
http://otn.oracle.com/ocm/jvelikanovs.html
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