Re: referencial conlumn contraints and inheritance

Stuart,

>   I am not sure where to post this.  This may be more of a wishlist
> item
> than a usage question.  I am new to postgresql 7.1.  Table
> inheritance
> in postgres seems wonderfull.  Is there the capability now or any
> plans to extend support for inherited tables in column constraints.
> One
> example is a travel db where several tables are defined as:

There have been, as I understand it, several improvements made to
inheritance and constraints in 7.2 (released soon, really!).

However, you're potentially in for a world of painful workarounds here.
REFERENCES constraints are part of a Relational DBMS system; Inheritance
is an OODB concept. The two do not, IMHO, mix easily. Further, current
implementations of table inheritance are largely proprietary, meaning
that your application becomes impossible to part across platforms.

If I were designing your database, I would forget about inheritance, and
build it completely relationally, either with an tree-structured Areas
table keyed to area subtypes, or with heirarchical tables of country -->
region --> province --> city etc. Which structure you use depends
largely on the rest of the application.

However, keep in mind that a lot of people (the Postgres core team
included) do not agree with me about inheritance and its limitations.

-Josh

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