Re: ts_rank

On Thu, May 19, 2011 at 10:42 PM, Kevin Grittner
<Kevin(dot)Grittner(at)wicourts(dot)gov> wrote:
> Robert Haas  wrote:
>> Mark  wrote:
>
>>> Could somebody explain me on which methods is based ts_rank and
>>> how it works?  I would appreciate some articles, if exist.
>
>> As far as I can tell, our documentation contains no useful
>> information on this topic whatsoever. :-(
>
> There's some potentially useful information here:
>
> http://www.postgresql.org/docs/9.0/interactive/textsearch-controls.html#TEXTSEARCH-RANKING

Ah, yes. I didn't read that carefully enough. That is useful, but it
doesn't really explain how it works.

> Although I don't know if it addresses Mark's question very well.
> Personally, I wonder how relevant ts_rank will be after knn-giswt
> is out....

I don't see why it would be any less useful... though if someone could
find a way to KNN-ify such searches, I'm sure there would be a lot of
very happy users. Seems pretty difficult, though.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company