There is the source code and explanation in the postgresql tarball:
contrib/spi/refint.*
I think referential integrity will be implemented soon as part of the
distribution. It is still at a project level, but you can read about it
here: http://www.postgresql.org/projects/devel-refint.html
On Wed, 19 Jan 2000, Daniel Spratlen wrote:
> I am a MIS student at the University of Georgia. I am doing a project
> for my Systems Analysis and Design class, and I am using PostgreSQL for
> the Database. I have taken a data management class and we always used
> foreign keys. I used a win32 program written by Power Soft called Data
> Architect. I used the PostgreSQL odbc drivers to interface with the
> linux box with the database on it. The reason I am writing all this, is
> that it created all the tables, indexes, and sequences just fine, but it
> skipped over the foreign keys. I understand that a trigger can be used
> instead of a foreign key, and I have read an explanation for this reason
> at
> http://www.mysql.org/Manual_chapter/manual_Compatibility.html#Missing_Foreign_Keys
>
> I was wondering if this is the same reason that PostgreSQL doesn't use
> foreign keys, and I was wondering exactly how to use the triggers
> instead of the foreign keys. Sorry for a long story in my message.
> Thanks in advance for the help.
> Daniel Spratlen
> spratlen@arches.uga.edu
>
>
> ************
>
>