Andy,
Here is what is happening.
The subfile is allocated to have only 13 records. Every 13 records, it
is reallocating the size of the subfile to make more room. So by the
time you have reach record 3200 during the initial load, you have
"reallocated" the subfile 246 times. Every time the system
"reallocates" the subfile, it has to move it to another copy that is 13
records bigger and then delete the old one.
If you know that you are going to be loading that many records, it would
decrease your original response time by increasing the SFLSIZ to a much
larger number your 4000 may be exactly what you need for a short term
fix.
Sharon
-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Andy Devries
Sent: Tuesday, January 18, 2011 2:52 PM
To: RPG programming on the IBM i / System i
Subject: RE: Subfile initial load very slow
Thanks Gary - I've set up the SFLSIZ= 13 AND SFLPAG = 12. I thought
this would do a page at a time but display the next page (and keeping
the original) when you do a page down??
Maybe I should set the SFLSIZ to be 4000?
-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Gary Thompson
Sent: Tuesday, January 18, 2011 12:10 PM
To: RPG programming on the IBM i / System i
Subject: Re: Subfile initial load very slow
One possible approach is to re-write as a "page (or two) at a time"
subfile
This requires your program to keep track of the user's current position
in
the data - not trivial the first time you develop this style -
but your response time should be very consistent regardless of
the
amount of data because only 15-30 subfile records
are loaded at any time.
My guess is the page at a time approach would be a major re-write, so
maybe more detail about how the data is loaded and
how many sub file records are populated would expose another
issue. After all, populating 3000 subfile records could
require a bunch of I-O, depending on your database.
Andy Devries <andyd@xxxxxxx>
Sent by: rpg400-l-bounces@xxxxxxxxxxxx
01/18/2011 12:30 PM
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RPG programming on the IBM i / System i <rpg400-l@xxxxxxxxxxxx>
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Subject
Subfile initial load very slow
I've been scratching my head about this one for some time. This is an
RPG400 program. I have a subfile that is loaded from a file that only
contains 3200 records. The initial load takes a long time (over a
minute). In subsequent calls to the same program, it responds much
better
(2-3 seconds). I've gone into debug - doesn't seem to hang at any
location. I've watched it process (WRKACTJOB) and it seems to do the
same
process. I have looked at locked records - doesn't seem to be a
problem.
Can anyone suggest other techniques for debugging this problem. As you
can imagine, the users don't like the long delay.
Andy
midrange.com
