RE: SQL Triggers and Multiple Member Database Files>

Charles,

You wrote:

"First you say "that the iSeries OS is not a true RDBMS."  Then you say
"if you want the normal concepts, features and functions of standard SQL
and DB2 to work as they do in the other true RDBMSs, then do as they do;
 re-architect your databases and applications in DB2/400 like the rest"

If the iSeries wasn't a true RDBMS, then you couldn't implement a RDB
and its corresponding applications on the iSeries.

I grant you, many legacy DBs on the iSeries don't follow RDB standards.
 But that doesn't stop the iSeries from being a true RDBMS.  I've said
it before, it's just as easy to implement a non-RDB and applications on
Oracle and SQL server is it is on the iSeries."


Yep, I say what I said because the iSeries is an RDBMS look-alike, like
MS Access, but closer to the real thing that MS Access.  The OS/400 has
been extended to provide RDBMS-like capabilities.  IBM had to make it
look like the other implementations of DB2 by extending the basic
S/38-OS/400 architecture to have DB2-like features and allow you to
access data both ways.   That's NOT allowed in a true RDBMS on the
market.    For instance, DB2 on MVS uses the native VSAM file concepts
to store its data BUT its not truly VSAM because you can't access DB2
data using VSAM utilities unlike what you can do on the iSeries.   In
the real DB2 and Oracle worlds, either your creating and accessing
TABLES, VIEWS, etc. using SQL or your not.  You can't access DB2 and
Oracle tables using a READ or a CHAIN, etc.  If you want to use READS,
you create files under whatever the native file structures is and in
that case you're not using an RDBMS.  

And, to your point about creating a non-RDB on Oracle, don't see how
you come to that conclusion since creating a RDB in a real RDBMS is, by
definition, an RDB even though it may be VERY POORLY architected like
some sort of flat-file or multi-member database.  

You are right, however, MOST iSeries legacy flat-file and multi-member
data file DBs don't follow RDB architectural standards, even though they
could given the RDBMS look-alike functions  implemented in DB2 on the
iSeries. 

For those that wish to make their applications look and act like the
rest of the DB2s and Oracles, you have to embrace the real relational
world in the way you think, act, speak, architect, etc.  It will be
hard.  I was for all the folks that had legacy apps under MVS, VM, VSE,
UNIX, etc.  In the real RDBMS  world you won't EVER here them referred
to their native file structures like PF and LF,  multiple member files
or what have you.   One of the basic advantages of a real RDBMS is you
don't EVER worry, nor talk about the native file structure.  

Folks that moved to the real RDBMs made the leap(wow, its been about 15
years), although with lots of teeth gnashing and speaking about the
"good old days" of legacy, non-relational application development.   So
too must the iSeries world.  They have to stop trying VERY HARD to keep
their data and application architecture looking like it was before but
using SQL where it suits them and speaking in RDBMS terms on occasion.  
 

I'll say it again,.. the quicker the iSeries world truly moves to
thinking, speaking, architecting and acting like they are working in a
real RDBMS, the quicker IBM can actually architect the OS and DB2/400 to
where it IS a true DB2.  Also, it will be quicker and easier for the
rest of the IT world to consider the iSeries something to be considered
when they are making a buying choice between Oracle under Windoz or some
flavor of Unix or DB2 UDB under AIX, VM, VSE or MVS.   The more the
iSeries world stays in their esoteric (perceived as proprietary) world,
the more they doom their platform AND their careers to extinction.   
And I don't want that to happen.

Take care,

Dave