Re: Service Program Overhead

[James Perkins <jrperkinsjr@xxxxxxxxx>]

Oops, yes what was supposed to be CPYTOIMPF, sorry about that.

It seemed to work pretty fast for me. I prefer to write a CSV as you suggest
though directly from RPG. I hate using work tables if I don't have to.

--
James R. Perkins
http://twitter.com/the_jamezp


On Fri, Nov 13, 2009 at 11:12, Kurt Anderson
<kurt.anderson@xxxxxxxxxxxxxx>wrote:

> Hi James,
>
> I don't know if things have changed, but historically I've always seen
> significantly slower times when using CPYTOSTMF than when writing to the IFS
> directly from RPG via APIs (and writing directly from RPG to the IFS also
> has the benefit of skipping intermediary processing such as writing to a
> temp file before passing it along).
>
> I know you said you used CPYFRMINPF to export the file to CSV, but I guess
> that confuses me b/c from the looks of it that command copies the file from
> the IFS to your library.
>
> Some info on writing directly to the IFS via RPG:
> http://www.news400.com/resources/clubtech/tnt400/bo400ng/AS400Q0167.htm
>
> -Kurt Anderson
>
> -----Original Message-----
> From: rpg400-l-bounces@xxxxxxxxxxxx [mailto:rpg400-l-bounces@xxxxxxxxxxxx]
> On Behalf Of James Perkins
> Sent: Friday, November 13, 2009 12:45 PM
> To: RPG programming on the IBM i / System i
> Subject: Service Program Overhead
>
> Hello All,
> I had to write a program to write DB data to a stream file in comma
> delimited format. No problem, done it many of times. Then I ran into a
> problem, running the program seemed to take hours. Well, I determined that
> was a bad subprocedure on my part, so I fixed that and it now takes only
> about 5 minutes to run.
>
> While doing this doing this I tried a couple of other approaches. I wrote
> the data to a table and used CPYFRMIMPF to export it to a CSV, this took
> about 1 minute 40. I also wrote a simple Java program to execute an SQL
> statement and write the results to a stream file, this took about 1 minute
> 10. ** Note, there was no scientific approach to the time calculation, just
> simple start and end times.
>
> It seems that the invocation of subprocedures in a service program
> significantly slows down performance. I invoke 2 subprocedures on each
> write
> to the stream file, a replace all subprocedure and the write line
> subprocedure. So, for the question, what kind of overhead is there when
> invoking subprocedures from a service program? I'm sure there is
> information
> on this, I just can't seem to find it.
>
> Thanks in advance,
> --
> James R. Perkins
> http://twitter.com/the_jamezp
> --
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