Re: [HACKERS] LZ compressing data type

>
> Hi,
>
> I just committed some changes that require an initdb.
>
> New are the discussed, simple LZ compressor, placed into
> /utils/adt/pg_compress.c, and a new lztext data type based on
> it. You'll find a fairly detailed description of the
> compression algorithm in the comments at the top of
> pg_lzcompress.c.

One question.

You say this is an LZ algorythm. Is this the same as LZW, as in the
same kind that gifs use. If so, are we sure that this algorythm is not
covered by the Unisys patent? Their patent is on the algorythm for
compression not on gifs themselves.

If it is, you are liable for a $5,000 fee to use it throughout your
site, or a per-licence fee if you are distributing (thay are worked out
on a per case basis but typical licences are $5 per unit sold from what
I am told).

I came across this problem with a gif manipulation program that *I
WROTE FROM SCRATCH* and had to switch to using the libungif
compression routines.

Just thought Id mention this, in case it has been overlooked.

~Michael