RE: Logical File or OPNQRYF or anyother way ?

[michael@xxxxxxxxxxxxxxxxxx]

Ken...what do you mean by this?

SQL is also an option for batch programs, but personally I find SQL to
be a
real PITA for many reasons, not the least of which is the poor
integration
of SQL into the RPG compilers (not the fault of the compiler folks).

I think it integrates OK with RPG. I'd like it to be free form, but
that's more of a nusiance than a problem. What am I missing?

> -------- Original Message --------
> Subject: Re: Logical File or OPNQRYF or anyother way ?
> From: "Ken Sims" <mdrg5003@xxxxxxxxx>
> Date: Fri, March 04, 2005 11:36 am
> To: midrange-l@xxxxxxxxxxxx
> 
> Hi Malini -
> 
> >I have a physical file which has millions of records, and this physical 
> >file gets updated quite frequently by various programs in the application.
> >
> >I have to develop 2 programs pertaining to an enhancement request.
> >
> >Program 1
> >
> >Needs to read the file selectively based on two fields of the physical 
> >file , perform calculations on the selected records and update them. There 
> >is no existing logical file on the physical with these 2 fields as a key
> >
> >Program 2
> >
> >Needs to read (only)the file selectively. File is opened in input mode only.
> >
> >Which is the more efficient method in each case - creating a logical file 
> >with the 2 fields as key or using an openquery with select on the 2 fields 
> >before each program is called. Any other efficient way ?
> 
> The most efficient way is to have a logical file.
> 
> If either of the programs is interactive, or if either program is going to 
> be run frequently, definitely make a logical file.
> 
> If both are going to run in batch and not very often (like a month-end 
> program), then an OPNQRYF with record selection would probably be acceptable.
> 
> >Also :- What are the scenarios where a logical file is preferred over an 
> >open query file and vice-versa ?
> 
> My response above pretty covers that.  Additionally, even for an infrequent 
> batch program, if you need to do keyed operations (rather than just 
> processing all of the selected records sequentially), the logical file is 
> better.  In that case the logical file could be MAINT(*REBLD) so that the 
> access path would be built when the file is opened.
> 
> SQL is also an option for batch programs, but personally I find SQL to be a 
> real PITA for many reasons, not the least of which is the poor integration 
> of SQL into the RPG compilers (not the fault of the compiler folks).
> 
> --
> Ken
> http://www.ke9nr.net/
> Opinions expressed are my own and do not necessarily represent the views of 
> my employer or anyone in their right mind.
> 
> -- 
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