Re: lztext and compression ratios...

Tom Lane wrote:
> JanWieck@t-online.de (Jan Wieck) writes:
> >     One  thing  to  keep  in mind is that the LZ algorithm you're
> >     thinking of must be distributable under the terms of the  BSD
> >     license.  If it's copyrighted or patented by any third party,
> >     not agreeing to these terms, it's out of discussion and  will
> >     never  appear in the Postgres source tree.  Especially the LZ
> >     algorithm used in GIF is one of these show-stoppers.
>
> As long as you brought it up: how sure are you that the method you've
> used is not subject to any patents?  The mere fact that you learned
> it from someone who didn't patent it does not guarantee anything ---
> someone else could have invented it independently and filed for a
> patent.

    Now that you ask for it: I'm not sure. Could be.

> If you can show that this method uses no ideas not found in zlib,
> then I'll feel reassured --- a good deal of legal research went into
> zlib to make sure it didn't fall foul of any patents, and zlib has
> now been around long enough that it'd be tough for anyone to get a
> new patent on one of its techniques.  But if SLZ has any additional
> ideas in it, then we could be in trouble.  There are an awful lot of
> compression patents.

    To  do  so  I  don't know enough about the algorithms used in
    zlib.  Is there someone out here who could verify that  if  I
    detailed enough describe what our compression code does?


Jan

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