RE: Tables and PFs

["Evan Harris" <spanner@xxxxxxxxxx>]

Hi Vern

I understand the difference between tables created via SQL vs DDS: verify at
read vs. verify at write, ability to use EVI's etc. I agree the creation
details are important if you are looking at database optimization or shop
standards going forward.

That said, in my opinion, they are more rightly called tables as a general
database term, as it's only an accident of history  that we on the iSeries
call them files. 

In particular when discussing them with a non-iseries person's perspective
(which for one reason or another is the impression I got from the OP) the
general term "tables" more accurately expresses the concept of what a
physical file is, regardless of how it was created. Like I said, to me this
is only a detail that's relevant to an iSeries guy.

How tables get created is important for all the reasons you point out, but I
don't think we should start calling SQL created PF's tables and DDS created
PF's files, do you ?

BTW, I don't think you're saying that :) but I did get the impression that
the OP was using the terms in that way, and my view (pun intended) is that
that is not a correct use of terminology.

Regards
Evan Harris

-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Vern Hamberg
Sent: Wednesday, 13 January 2010 4:12 p.m.
To: Midrange Systems Technical Discussion
Subject: Re: Tables and PFs

Hi Evan

I agree that for existing tables/PFs, that it is not too important. It 
might become more important when looking at creating new objects, where 
there can be good reasons to take advantage of performance improvements. 
A discussion of these advantages does require some terminological 
exactitude, perhaps, at least for a short period of time.

Vern

Evan Harris wrote:
> Hi David
>
> No, there really isn't; a PF on the iSeries is basically what the rest of
> the IT world else calls a table. The way I look at it is:
>
> - A table is a thing that contains rows and columns and is part of a
> database
> - A file is a thing that lives in the file system
> - The database will almost certainly live within the file system so the
> distinction is important
>
> As to your tables from the parameter file they would be better termed
lookup
> tables or even hashes.
>
> The semantics of what constitutes a table vs. a physical file on the
iSeries
> is indistinguishable and inconsequential to the rest of the world.
>
> It shouldn't bug you that he says this, it's IT Jargon as opposed to an
> iSeries sub-dialect.
>
> Regards
> Evan Harris