Re: RPG IV program - comments requested

[Jim Langston <jlangston@xxxxxxxxxxxxxxxx>]

Comments in line

"James W. Kilgore" wrote:

> You have the basics down, but I would do two things differently.
>
> Not that your code is wrong, but,
>
> 1) I have found that using UP to process a file can create a problem.  Since
> every record gets locked, update or not, you can fall into a lock wait.  By 
>using
> the file twice, once as IP then again as UF you gain blocking and only lock 
>the
> records that need an update.  If the file being processed does not have a 
>unique
> key, get the record to update by record number which can be given to you from 
>the
> file feedback data structure.

Interesting...  I wouldn't need to do that in this program, as this is a 
transmission

file and is being used exclusively, and my production files are all keyed so I
normally
do a CHAIN, which means it is a UF usually, and I only read the records I am 
actually

wanting to change.  Our primary file is almost always Input only.  But this is 
a good

idea and I will keep it in mind.


> 2) Using the UPDAT command is more overhead than you really need.  Again 
>there is
> nothing wrong with UPDAT, but we prefer an EXCPT with only the fields that are
> being changed listed.  (Besides it makes it very clear as to which field 
>values
> the program affects.

Actually, I find UPDATE much easier to understand myself, from a self 
documenting
point of view.  If I come across a program that is changing fields, then does an
UPDATE
I know what it is doing.  But, when I come across a program that has an EXCEPT 
to
out output spec, I have to jump down and see what is being updated.

There may be some additional overhead it writing the record, but I don't think 
that
could
be anything significant to a program.

Regards,

Jim Langston

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