Re: Table Definitions DDS or SQL?

Hi,

I'm trying to convince the rest of the IT programmers to do the same, but 
it's a hard slog.

make your collegues and even your managers read the following article.
I'm sure they will be convinced using SQL-defined tables will be the better 
choice.

Modernizing Database Access
The Madness Behind the Methods
By Dan Cruikshank
http://www-03.ibm.com/servers/eserver/iseries/db2/pdf/Performance_DDS_SQL.pdf

IMO there is only one disavantage of SQL-DDL compared with DDS-definition: 
In SQL reference files are not supported.
Sure a SQL table can be created as:
Create Table ...
      as Select ... From ReferenceFile

But the references are not stored in the system tables, i.e. in the system 
tables only the absolute definition (such as Char(20) or Dec(11, 2)) are 
stored. So, if you have to change a field/column definition, it is not enough 
to do a simple change reference file and actualizing the tables with a simple 
CHGPF. You have to change the field/columns definitions manually in every 
table, where those fields are defined, by using the SQL command ALTER TABLE. 

Mit freunlichen Grüßen / Best regards 

Birgitta Hauser

"Shoot for the moon, even if you miss, you'll land among the stars." (Les Brown)
"If you think education is expensive, try ignorance." (Derek Bok) 




----- Original Message ----- 
From: "Peter Levy" <plevy@xxxxxxxxxxxx>
To: "RPG programming on the AS400 / iSeries" <rpg400-l@xxxxxxxxxxxx>
Sent: Thursday, October 05, 2006 23:31
Subject: Re: Table Definitions DDS or SQL?

All new files that I created are done with SQL scripts. I'm trying to 
convince the rest of the IT programmers to do the same, but it's a hard 
slog.

Mike wrote:

/me opens can of worms

Hey, I just thought of something. Do most people still use DDS for file
descriptions or have you moved to SQL tables? I can see pros and cons for
both. Thoughts?

  

-- 
Peter Levy
Alliance Shippers, IT Dept
Englewood Cliffs, NJ
Voice: 201-227-0400
Fax: 201-227-0925
Email: plevy@xxxxxxxxxxxx
AIM: pklevyalliance2

---------------
There are 10 kinds of people in the world;
Those who understand binary and those who don't.

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