Re: Suggestion for improving loop performance

[Scott Klement <rpg400-l@xxxxxxxxxxxxxxxx>]

Hello,

It would be hard to tell you the best performing method without actually 
writing the code and benchmarking the alternatives.  Here are ways to do 
this:

1) Keep what you have.

2) Instead of SCAN into an array, try %SCAN in a loop.  You could make 
this all one loop that way.

3) Instead of using SCAN/%SCAN you could consider looping thru the 
characters one-by-one -- also make it all one loop.

Check each of these methods to see which performs best.

Also, I would definitely eliminate the horrible %CHECKR -- this is a 
huge time-waster.  %TRIMR is no better. Instead, use a VARYING field so 
the trimming/checking isn't needed.

-SK



On 5/19/2015 1:17 PM, Singh, Ashwani (Lake Mary) wrote:
> Folks,
>
> We are trying to process a 69 million records file which is taking 5 hours plus to load into another file. (We have Block *Yes specified for the input file (with 69M records) We need to bring the processing down for sure..
>
> We are trying for the multithread as well..
>
> There are two crucial loops that run in this single program and causing trouble.
>
> The first loop takes round about .6 seconds/rec processed  the other one .4 seconds.
>
> Our file is a flat file and is | delimited ..
>
> Loop 1
> D ARRAY1       S           5 0  DIM(999)
> C    '|'          SCAN        DATA            ARRAY1
> C Eval X= 1
> C Eval A= 0
> C Dow ARRAY1(X) > 0
> C  Eval A+=1
> C Eval X+=1
> C ENDDO
>
>
>
>
> Loop2
> C DOW A < #Pipesreq (Number of pipes actually required)
> C Eval  Fileds = %subst(fileds:1:%checkr(' ':Fileds)) + '|'
> C eval A+=1
> C ENDDO
>
>
> Any suggestion will  be highly appreciated..
>
>
>
> Thanks,
> Ashwani Singh