RE: Variable length fields

["Don Tully" <dtully@xxxxxxxxxx>]

Pete,

It is easy to create a varying length field in either DDS or SQL.

In DDS the field is defined as any other character field is defined and then
add keyword VARLEN(nnn) where nnn is less than maximum length defined.
VARLEN(nnn) defines the default length stored inline as a part of the PF.
If the data length exceeds len(nnn) then a variable extension is created.
For performance reasons you want to avoid that most of the time without
wasting disk space.  In RPG just remember to use   VARFLD =
%TRIMR(LongChar).  Otherwise you end up with VARFLD padded with blanks.

There certainly would be nothing wrong with using CREATE TABLE to accomplish
the same result.  I use both methods as the situation warrents without any
problems.

It is also easy to deal with these fields in RPG if that is an issue.  I can
see no reason to put this type of data into another library.

Don Tully
Tully Consulting LLC

-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx]On Behalf Of Pete Helgren
Sent: Thursday, January 27, 2005 12:46 PM
To: 'Midrange Systems Technical Discussion'
Subject: Variable length fields


I need to store a varying amount of text data in a field in a currently
non-existent table and I am pondering how best to approach creating it.
I'll be using Java as the programming language (and, yes, David, I'll move
this to the JAVA-400 forum if the details take us there).

I have primarily worked with PF's and DDS on the iSeries and done a little
bit of SQL (create collection, create table, alter table, etc).  What data
type would work best here?  Looks like  varchar would work.  Would that
recommendation change if you were using RPG to access the data?

If my PF's are all stored in libraries, is it best in this case to only use
the create table command to put it in a new collection, or could I put it in
an existing library (or perhaps I cannot even do this...?)

Any wisdom in approaching this would be appreciated.

Thanks,

Pete Helgren
Value Added Software, Inc
801.581.1154 x202

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