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History

PostgreSQL Daemon 55b113257c make sure the $Id tags are converted to $PostgreSQL as well ...		2003-11-29 22:41:33 +00:00
..
isbn_issn.c	make sure the $Id tags are converted to $PostgreSQL as well ...	2003-11-29 22:41:33 +00:00
isbn_issn.sql.in	make sure the $Id tags are converted to $PostgreSQL as well ...	2003-11-29 22:41:33 +00:00
Makefile	$Header: -> $PostgreSQL Changes ...	2003-11-29 19:52:15 +00:00
README.isbn_issn	Add missing /contrib files	2000-06-19 14:02:16 +00:00

README.isbn_issn

ISBN (books) and ISSN (serials)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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