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
midrange.com
