Re: Can I tryst in "physical ... direct" figures?

From: <J.Velikanovs_at_alise.lv>
Date: Fri, 24 Sep 2004 13:44:22 +0300
Message-ID: <OFF1A0C0D1.CAECADB1-ONC2256F19.0038939D-C2256F19.003B1A4C@alise.lv>

Terry,
thank you for interest on my post
The full PS report is available by using this URL: ftp://ftp.alise.lv/pub/oracle/to_oral/perf_IKSP_20040923.txt

Regarding your assumption:
>> are you doing a lot of sorting?

Statistic                                      Total     per Second    per

Trans

--------------------------------- ------------------ -------------- 
------------
sorts (disk)                                     286            0.0   0.0
sorts (memory)                             7,945,774          176.6  84.6
sorts (rows)                             594,066,774       13,201.2

6,326.1

Only 286 !? I don't think that 286 is a lot ;(

>> Does your Statspack report show a lot of direct path reads/writes?

Event                               Waits 
---------------------------- ------------ 
direct path write               1,492,422          0         12      0 
15.9
direct path read                1,111,255          0          6      0

11.8

Statistic                                      Total     per Second    per

Trans

--------------------------------- ------------------ -------------- 
------------
physical writes                           16,465,203          365.9 175.3
physical writes direct                    16,343,723          363.2 174.0

Dose DBWR use direct path to write dirty blocks to disk? If not then for DBWR work is just 121 480 writes from 16M.

This graph shows that is coleration between PW and PWD: ftp://ftp.alise.lv/pub/oracle/to_oral/dwr.JPG As you can see PWD distributed regulary during the day.

Jurijs
+371 9268222 (+2 GMT)

Thank you for teaching me.
http://otn.oracle.com/ocm/jvelikanovs.html

"Terry Sutton" <terrysutton_at_usa.net>
Sent by: oracle-l-bounce_at_freelists.org
24.09.2004 07:55
Please respond to terrysutton

        To:     <oracle-l_at_freelists.org>
        cc: 
        Subject:        Re: Can I tryst in "physical ... direct" figures?

It's not for me to tell you where you can tryst, or with whom.

But, getting back to direct read/writes... are you doing a lot of sorting? Are you doing a lot of LOB access? Does your Statspack report show a lot of
direct path reads/writes?

--Terry

Original Message ----- 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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Received on Fri Sep 24 2004 - 05:41:16 CDT