Subject RE: [IB-Architect] Table Inheritance
Author Ungod
-----Original Message-----
From: Jim Starkey [mailto:jas@...]
Sent: Tuesday, 18 July 2000 4:42 AM
Subject: [IB-Architect] Table Inheritance


Question 1: Does table inheritance simply mean attribute (fields,
triggers, primary keys, indexes) inheritance, or does it mean a
a unified semantic model?

> I'd say both, the ledger example is a good reason for the unified model,
but the multiple triggers/definition by inheritance is a good reason for
simple inheritance.

Question 2: Are primary key inherited? Choices: a) yes, b) no,
c) declared primary key of extension table appended to primary
key of base table (problem is that uniqueness of base table is

> See other peoples comments, they've given a good run down.

Question 3: Is multiple inheritence necessary? Most language
designers would say that multiple inheritence is mother natures
way of telling you that your design is screwed up. Multiple
inheritence in C++ is moby complicated and usually does the
wrong thing. Java dump it in favor of single inheritance
plus implementation of interfaces (polymorphism without
representation). What is the minimal feature set we can live

> Let me tell you how many multiple derivation declartions i have made in
the 15 or so years i've coded in c++. 5. yes, 5 declartions of objects with
multiple inheritance. Answer enough?

Jim Starkey

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