Jan Wieck wrote:
>> Yes, but what about referential integrity? Can I have a table column
>> reference a column from Entities*? In my experimentation, this is not the
>> case.
>
> Referential integrity doesn't work with inheritance, and will
> not in 7.1.
>
> It isn't possible to put a unique constraint on a column of
> Entities* (AFAIK). So that a SELECT pkey FROM Entities will
> never return any duplicates? The RI implementation of
> PostgreSQL doesn't insist on such a unique constraint to
> exist up to now, but it is required by the SQL specs and thus
> we'll do so someday.
The corollary of using RI on an inheritance tree is that there should be a
unique index on the primary keys of the whole tree. If constraints could be
inherited, this would become available.
--
Oliver Elphick Oliver.Elphick@lfix.co.uk
Isle of Wight http://www.lfix.co.uk/oliver
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