p175 wrote:
Dear Guru's
Can anyone please direct me to articles, documents or indeed help
explain in 'english' the benefits and advantages of using TYPEs,
HEIRARCHYs, TYPE TABLEs and METHODs ?
I've tried reading all I can on the topic but I simply end up wondering
WHY ?
Many thanks, Tim
User defined DISTINCT types are essentially type defs. There benefit is
that you can change the basetypes without having to hunt down all the
usages. (imaginge changing an employee id from smallint to integer
through the DBMS and app).
User defined structured types are a different matter, and so is
everything attached to it.
What you have here is a different (OO) way of thinking.
But one thing is for sure. Structured types and what is associated to
them are tough on an RDBMS.
I would NOT use them for a vanilla app.
My guess is that XMLTYPE and XQUERY replace most of the OO features of
ORDMS.
I developed typed views and was involved with structured data types. So
I'm not an anti-oo person. I just believe that was some sort of IT
fashion to bring those into RDBMS with little if any return on
investment. Ues OO in Java, C#, take your pick. But stick with
relational in the database.
Just my two cents canadian looking into the rearview mirro.
Cheers
Serge
--
Serge Rielau
DB2 SQL Compiler Development
IBM Toronto Lab
