Re: Record blocking optimization

[Alan C <steelville@xxxxxxxxxxx>]

Hi Tony,

The cycle is a magnificent tool, or was, in its time. :-)  One 
programmer at a place I used to work took a report program that was 
running about two days' time at one client site, and brought it down to 
a couple of hours, just by changing it to use the cycle, on the System 38.

About the RPG cycle, if you came into the RPG world at RPG-IV, and have 
not used the cycle, it would be a little much to learn it just for this. 
I rarely ever use it anymore, maybe once every several hundred projects, 
except for really simple straightforward reports.   In resolving this 
situation, Joel's seq-only comments would probably be your best fit due 
to your coming in at this time.

The cycle generates a good amount of coding for you if it's a straight 
report that reads through the whole file, but if you get a little 
complicated in your modifications it can get in the way. That's one of 
the reasons even most programs that would fit the cycle, I don't use it, 
depending.

I'm curious as to others' view on using the RPG cycle anymore, or the 
value in learning it for newcomers. I'm not even that sure myself..

- Alan

> Thanks for the info.  That 'sequential only' language had me worried.  
>
> <snip>
>  
>
> > That said, on first listen, this sounds like it might lend itself to the old RPG cycle, which still works in RPG-IV, if the idea is to optimize. It's hard to beat the cycle, though I'm sure buffering optimization would get close.  Using primary and secondary, the compiler sets up the optimum block size.
> >    
> </snip>
>
> My curiosity is piqued.  My mindset has been on avoiding the cycle,
> and just optimizing this thing as best as I can (read blocking, using
> all DSs for input/output/updates, etc).
>
> Now this is a little humbling, but I am a late comer to the game of
> RPG (I have used IV only, and was taught to avoid the cycle at all
> costs), and I have never written a pgm using the cycle AND primary AND
> secondary input files.  I know that if you specify a file as input
> primary, every record will be read from the file, and the calc specs
> will be repeated for each record, but I am not sure how the secondary
> file plays into this.  Is a record automatically read from the
> secondary file also?
>