Re: Record blocking optimization

[Alan C <steelville@xxxxxxxxxxx>]

Hi Tony.

I believe the records will still be input in keyed order, but someone 
with specific memories could answer more definitively.

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.

- Alan


> I am trying to optimize a batch program that must read through two
> copies of a file, and compare the records to update one copy with
> differences.  Both files are declared as Input, keyed access, i.e.
>
>     FDFamly    IF   E           K Disk
>     FFamly     IF   E           K Disk
>
> I am trying to override the default read block size of 4k to the
> maximum of 128k.  As I understand it, if 204 records will fit in 128k,
> you can do an OVRDBF command, as such:
>
> RC=system('OVRDBF FILE(FAMLY)  SEQONLY(*YES 204)');
>
> So I have to specify SEQONLY(*YES) to set the buffer size.  Will the
> records still be read in keyed order?  I know that if I read in keyed
> order, some buffering happens, so if not with the OVRDBF command, how
> can I set the blocking size to the maximum?
>
>
>