ts_rank

On Tue, May 10, 2011 at 6:21 AM, Mark <Marek.Balgar@seznam.cz> wrote:

Could somebody explain me on which methods is based ts_rank and how it works?
I would appreciate some articles, if exist.
Thanks a lot for reply.

As far as I can tell, our documentation contains no useful information
on this topic whatsoever. :-(

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

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

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....

-Kevin

On Thu, May 19, 2011 at 10:42 PM, Kevin Grittner
<Kevin.Grittner@wicourts.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

There's some potentially useful information here:
http://www.postgresql.org/docs/9.0/interactive/textsearch-controls.html#TEXTSEARCH-RANKING

Thanks for reply. I was reading the documentation of PostgreSQL, but there
it is not written the name of the used methods. Everywhere there is written,
that ts_rank use standard ranking function. But it is difficult to say which
is the standard function.
Somewhere I found that it is maybe based on Vector space model and it seems
to be truth, because in the code of tsrank.c is counted the frequency of
words, but I am not sure of that :-(

--
View this message in context: http://postgresql.1045698.n5.nabble.com/ts-rank-tp4384614p4414631.html
Sent from the PostgreSQL - hackers mailing list archive at Nabble.com.

Mark wrote:

There's some potentially useful information here:
http://www.postgresql.org/docs/9.0/interactive/textsearch-controls.html#TEXTSEARCH-RANKING

Thanks for reply. I was reading the documentation of PostgreSQL, but there
it is not written the name of the used methods. Everywhere there is written,
that ts_rank use standard ranking function. But it is difficult to say which
is the standard function.
Somewhere I found that it is maybe based on Vector space model and it seems
to be truth, because in the code of tsrank.c is counted the frequency of
words, but I am not sure of that :-(

Oleg, Teodor, can you give me a description of how ts_rank decided how
to rank items? Thanks.

--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ It's impossible for everything to be true. +

Bruce Momjian wrote:

Mark wrote:

There's some potentially useful information here:
http://www.postgresql.org/docs/9.0/interactive/textsearch-controls.html#TEXTSEARCH-RANKING

Thanks for reply. I was reading the documentation of PostgreSQL, but there
it is not written the name of the used methods. Everywhere there is written,
that ts_rank use standard ranking function. But it is difficult to say which
is the standard function.
Somewhere I found that it is maybe based on Vector space model and it seems
to be truth, because in the code of tsrank.c is counted the frequency of
words, but I am not sure of that :-(

Oleg, Teodor, can you give me a description of how ts_rank decided how
to rank items? Thanks.

Any news on this question?

--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ It's impossible for everything to be true. +

I'm sorry, my plane to Nepal is waiting me :) I'll be back in the
midst of November. In short, ts_rank is based only on frequencies of lexems
and doesn't count distance between query lexems. Also, it supports only
primitive queries.

Oleg
On Wed, 12 Oct 2011, Bruce Momjian wrote:

Bruce Momjian wrote:

Mark wrote:

There's some potentially useful information here:
http://www.postgresql.org/docs/9.0/interactive/textsearch-controls.html#TEXTSEARCH-RANKING

Thanks for reply. I was reading the documentation of PostgreSQL, but there
it is not written the name of the used methods. Everywhere there is written,
that ts_rank use standard ranking function. But it is difficult to say which
is the standard function.
Somewhere I found that it is maybe based on Vector space model and it seems
to be truth, because in the code of tsrank.c is counted the frequency of
words, but I am not sure of that :-(

Oleg, Teodor, can you give me a description of how ts_rank decided how
to rank items? Thanks.

Any news on this question?

Regards,
Oleg
_____________________________________________________________
Oleg Bartunov, Research Scientist, Head of AstroNet (www.astronet.ru),
Sternberg Astronomical Institute, Moscow University, Russia
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(495)939-16-83, +007(495)939-23-83

Oleg Bartunov wrote:

I'm sorry, my plane to Nepal is waiting me :) I'll be back in the
midst of November. In short, ts_rank is based only on frequencies of lexems
and doesn't count distance between query lexems. Also, it supports only
primitive queries.

Thanks. Attached doc patch applied to head and 9.1.X.

---------------------------------------------------------------------------

Oleg
On Wed, 12 Oct 2011, Bruce Momjian wrote:

Bruce Momjian wrote:

Mark wrote:

There's some potentially useful information here:
http://www.postgresql.org/docs/9.0/interactive/textsearch-controls.html#TEXTSEARCH-RANKING

Thanks for reply. I was reading the documentation of PostgreSQL, but there
it is not written the name of the used methods. Everywhere there is written,
that ts_rank use standard ranking function. But it is difficult to say which
is the standard function.
Somewhere I found that it is maybe based on Vector space model and it seems
to be truth, because in the code of tsrank.c is counted the frequency of
words, but I am not sure of that :-(

Oleg, Teodor, can you give me a description of how ts_rank decided how
to rank items? Thanks.

Any news on this question?

Regards,
Oleg
_____________________________________________________________
Oleg Bartunov, Research Scientist, Head of AstroNet (www.astronet.ru),
Sternberg Astronomical Institute, Moscow University, Russia
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(495)939-16-83, +007(495)939-23-83

--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ It's impossible for everything to be true. +