Обсуждение: inheritance vs 1-1 relationship

Inheritance seems pretty nifty.  I am at a point where I would normall
create a 1-1 relation ship where the primary key of a table is also a
foreign key on another table but it seems like inheritance would
essentially do the same thing + save me from having to write joins in my
selects and having to do 2 part inserts.  Are there any drawbacks to
inheritance other than a decrease in portability?

culley

On Sat, 2003-05-17 at 21:36, culley harrelson wrote:
> Are there any drawbacks to
> inheritance other than a decrease in portability?

Inheritance is very nifty and, more importantly, better represents the
data of some problems.  I love it.

James Gregory and I have just had a short thread re: foreign keys into
inherited tables which you may wish to read (see archive).  It's not a
problem per se, but rather a minor shortcoming (IMO).

Some things to note with inheritance:
- indices are not created on subtable columns automatically
- the super- & subtables are distinct tables
- select really just does a union select on subtables
- alter and drop cascade to subtables

I haven't had any problems with inheritance and mostly think it's
wonderful.

-Reece

--
Reece Hart, Ph.D.                       rkh@gene.com, http://www.gene.com/
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