RE: logical and physical reads statistics using DSPFD

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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