Re: logical and physical reads statistics using DSPFD

[Igor Seremet <igor.seremet@xxxxxxxxx>]

You're correct.  This should have been posted to the MIDRANGE-L forum.
 That was my intent; must have picked the wrong email.

I appreciate your reply.  Thanks.


On Thu, 20 Jan 2005 09:02:22 -0500, Wilt, Charles <CWilt@xxxxxxxxxxxx> wrote:
> This post should probably be in MIDRANGE-L as it is OS related not Java.
> 
> In any event, as I understand it, when the query engine uses an index, it 
> doesn't update the stats.  However, with v5r3 there are some new stats kept 
> for indexes including how many times it was used.  These new stats can be 
> seen through v5r3 Ops-Nav.
> 
> More info here:
> http://publib.boulder.ibm.com/infocenter/iseries/v5r3/ic2924/index.htm?info/rzajq/indexstats.htm
> 
> or
> 
> http://tinyurl.com/5q8e4
> 
> Note that when you used native RPG access, the LF stats should have been 
> updated.  At least the "last used", I would have expect the # reads to have 
> also.
> 
> HTH,
> 
> Charles Wilt
> iSeries Systems Administrator / Developer
> Mitsubishi Electric Automotive America
> ph: 513-573-4343
> fax: 513-398-1121
> 
> 
> > -----Original Message-----
> > From: java400-l-bounces@xxxxxxxxxxxx
> > [mailto:java400-l-bounces@xxxxxxxxxxxx]On Behalf Of Igor Seremet
> > Sent: Wednesday, January 19, 2005 7:09 PM
> > To: java400-l@xxxxxxxxxxxx
> > Subject: logical and physical reads statistics using DSPFD
> >
> >
> > I use DSPFD command to display file description for a logical file.  I
> > am interested in the number of logical and physical reads;
> > specifically, the change in the number of either of those.  I was
> > under the impression that the example below would change these
> > statistics, but it does not.
> >
> > Simple example -- ran on VR51 & V5R3:
> >
> > create table iseremet/contact(name char(16), extension char(3))
> >
> > insert into iseremet/contact values('Craig','109')
> > insert into iseremet/contact values('Elvis','110')
> > insert into iseremet/contact values('Jon','106')
> > insert into iseremet/contact values('Jen','101')
> > insert into iseremet/contact values('David','103')
> >
> > CREATE INDEX ISEREMET/CONTACTI01 ON ISEREMET/CONTACT (NAME ASC)
> >
> > Now, when I run "select * from iseremet/contact  order by
> > name" in debug I get:
> >
> > **** Starting optimizer debug message for query .
> > Access path of file CONTACTI01 was used by query.
> > **** Ending debug message for query .
> >
> > Should this example have incremented the number of logical/physical
> > reads of the index itself?  Why?
> >
> > I have also tried reading the logical file (CONTACT01) using native
> > I/O, but same results.
> >
> >
> > Any input is greatly appreciated.
> >
> > Thanks
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> 
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