postgres

History

Bruce Momjian 07842084fe pgindent run over code.		1999-05-25 16:15:34 +00:00
..
Makefile	From: Garrett Wollman <wollman@khavrinen.lcs.mit.edu>	1998-08-17 03:35:05 +00:00
README	From: Garrett Wollman <wollman@khavrinen.lcs.mit.edu>	1998-08-17 03:35:05 +00:00
isbn.c	pgindent run over code.	1999-05-25 16:15:34 +00:00
isbn.sql	From: Garrett Wollman <wollman@khavrinen.lcs.mit.edu>	1998-08-17 03:35:05 +00:00
issn.c	pgindent run over code.	1999-05-25 16:15:34 +00:00
issn.sql	From: Garrett Wollman <wollman@khavrinen.lcs.mit.edu>	1998-08-17 03:35:05 +00:00

README

This directory contains definitions for a couple of PostgreSQL
external types, for a couple of international-standard namespaces:
ISBN (books) and ISSN (serials).  Rather than just using a char()
member of the appropriate length, I wanted my database to include
the validity-checking that both these numbering systems were designed
to encompass.  A little bit of research revealed the formulae
for computing the check digits, and I also included some validity
constraints on the number of hyphens.

The internal representation of these types is intended to be
compatible with `char16', in the (perhaps vain) hope that
this will make it possible to create indices of these types
using char16_ops.

These are based on Tom Ivar Helbekkmo's IP address type definition,
from which I have copied the entire form of the implementation.

Garrett A. Wollman, August 1998