inheritance vs 1-1 relationship

Started by culley harrelsonalmost 23 years ago2 messagesgeneral
Jump to latest
#1culley harrelson
culley@ml1.net

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

#2Reece Hart
rkh@gene.COM
In reply to: culley harrelson (#1)
Re: inheritance vs 1-1 relationship

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/
Genentech, Inc. 650/225-6133 (voice), -5389 (fax)
Bioinformatics and Protein Engineering
1 DNA Way, MS-93 http://www.in-machina.com/~reece/
South San Francisco, CA 94080-4990 reece@in-machina.com, GPG: 0x25EC91A0