Re: [HACKERS] LZ compressing data type

From: Philip Warner <pjw(at)rhyme(dot)com(dot)au>
To: wieck(at)debis(dot)com (Jan Wieck), wieck(at)debis(dot)com
Cc: grim(at)argh(dot)demon(dot)co(dot)uk, pgsql-hackers(at)postgreSQL(dot)org
Subject: Re: [HACKERS] LZ compressing data type
Date: 1999-11-18 03:26:05
Message-ID: 3.0.5.32.19991118142605.00c63a70@mail.rhyme.com.au
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

At 03:23 18/11/99 +0100, Jan Wieck wrote:
>
> From the very beginning of US patent No. 4,558,302 (the thing
> behind Unisys's LZW):
>

The other thing to remember is that there are a very large number of
countries in which this patent does not apply because it was not even
applied for until after the alogorithm was made public. In the first
publication of the LZW algorithm, there was no patent notice, but I think
the US patent had been applied for.

For US-based distribution sites, however, you may find the threat of legal
action from a large company is enough to make it less desirable to
distribute.

FWIW, I think Unisys patented the LZW algorithm only.

It's probably a bit late to ask, but how difficult would it be to
generalize your code to use the compressor/encryption library of choice?
zlib and pgp spring to mind. This would kill three birds with one stone.

----------------------------------------------------------------
Philip Warner | __---_____
Albatross Consulting Pty. Ltd. |----/ - \
(A.C.N. 008 659 498) | /(@) ______---_
Tel: +61-03-5367 7422 | _________ \
Fax: +61-03-5367 7430 | ___________ |
Http://www.rhyme.com.au | / \|
| --________--
PGP key available upon request, | /
and from pgp5.ai.mit.edu:11371 |/

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Tom Lane 1999-11-18 04:28:23 Re: [HACKERS] LZ compressing data type
Previous Message Jan Wieck 1999-11-18 02:23:41 Re: [HACKERS] LZ compressing data type