Re: Switching to SQL - changing the way we've always done things(was:SQLfor performance-etc.)

----- Original Message -----
From: "Richard B Baird" <rbaird@esourceconsulting.com>
To: "Midrange Systems Technical Discussion" <midrange-l@midrange.com>
Sent: Thursday, January 09, 2003 3:04 PM
Subject: Switching to SQL - changing the way we've always done things
(was:SQLfor performance-etc.)


> just a superficial switch to SQL processing (imbedded selects/fetches,
etc)
> doesn't appear to me to have a big advantage over traditional io.  where
> you get to the real savings, it seems from reading most of these posts, is
> in RI, cascading deletes, triggers, view and index tuning and such.

right

> which begs the question:  how do you implement such a monster, on an
> existing application, without a major re-design/re-write of the logic in
> nearly all of your programs?
>
> for instance:  what's the good in having RI at the database level when all
> your programs still do the 'chain   if not %found, error' routine?

Well, for one, new applications can take avantage of it. If you are not
changing code for any reason, then you have no reason to consider using SQL
instead of native I/O or DDS. In a perfectly static enviornment, you are
right, it buys you nothing. Just keeps you busy.

> setting up RI for a database does you no good, and probably harms, unless
> you make the corresponding application changes.  a daunting task just to
> ponder, let alone implement.


Harm is probably too strong a word. If your business rules say that
something should never exist without something else existing first... then
is it harmful to find a program in existance that is violating that rule?

And while blind application of RI can cause existing programs to "double
check" things, in a changing environment with new applications comming
online, the benefits may very well outweigh the performance issue of double
checking RI on old, unchanging applications.

Hard? Yes. Daunting? Maybe. But what in our jobs isn't. You want simple? Dig
ditches. (Oh, hell, even that's complicated today with everything we've
buried underground.... 1-800-b4u-digg)

===========================================================
R. Bruce Hoffman, Jr.
 -- IBM Certified Specialist - iSeries Administrator
 -- IBM Certified Specialist - RPG IV Developer

"When I die, I want to die like my grandmother who died peacefully
  in her sleep. Not screaming like all the passengers in her car."

    - Author Unknown