Re: Comparing tsearch2 vectors.

From: Achilleus Mantzios <achill(at)matrix(dot)gatewaynet(dot)com>
To: Rajesh Kumar Mallah <mallah(at)trade-india(dot)com>
Cc: pgsql-sql(at)postgresql(dot)org
Subject: Re: Comparing tsearch2 vectors.
Date: 2004-07-12 12:03:04
Message-ID: Pine.LNX.4.44.0407121454040.3671-100000@matrix.gatewaynet.com
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O kyrios Rajesh Kumar Mallah egrapse stis Jul 12, 2004 :

>
>
> Dear Mantzios,
>
> I have to get set of banners from database in
> response to a search term. I want that the search term
> be compared to the keyword corresponding to the
> banners stored in database. current i am doing an
> equality match but i woild like to do it after stemming
> both the sides (serch term and keywords).

You could transform your search terms so that there is the "&"
separator between them. (& stands for "AND").
E.g. "handicrafts exporter" becomes "handicrafts&exporter"
And then
select * from <your table> where idxfti @@ to_tsquery(<searchterms>);

where idxfti is your tsvector column.

E.g.
# SELECT to_tsvector('handycrafts exporters') @@ to_tsquery('handycraft&exporting');
?column?
----------
t
(1 row)

>
> So that the banners for the adword say 'incense exporter' is
> shown even if 'incenses exporter' or 'incense exporters' is
> searched.
>
> I hope i am able to clarify.
>
> Regds
> Mallah.
>
> Achilleus Mantzios wrote:
>
> >O kyrios Rajesh Kumar Mallah egrapse stis Jul 12, 2004 :
> >
> >
> >
> >>Hi,
> >>
> >>We want to compare strings after stemming. Can anyone
> >>tell me what is the best method. I was thinking to compare
> >>the tsvector ,but there is no operator for that.
> >>
> >>
> >
> >I'd tokenize each string and then apply lexize() to get the
> >equivalent stemified
> >word, but what exactly are you trying to accomplish?
> >
> >
> >
> >>Regds
> >>Mallah.
> >>
> >>
> >>
> >>tradein_clients=# SELECT to_tsvector('handicraft exporters');
> >>+---------------------------+
> >>| to_tsvector |
> >>+---------------------------+
> >>| 'export':2 'handicraft':1 |
> >>+---------------------------+
> >>(1 row)
> >>
> >>Time: 710.315 ms
> >>tradein_clients=#
> >>tradein_clients=# SELECT to_tsvector('handicrafts exporter');
> >>+---------------------------+
> >>| to_tsvector |
> >>+---------------------------+
> >>| 'export':2 'handicraft':1 |
> >>+---------------------------+
> >>(1 row)
> >>
> >>Time: 400.679 ms
> >>tradein_clients=# SELECT to_tsvector('Hi there') = to_tsvector('Hi there');
> >>ERROR: operator does not exist: tsvector = tsvector
> >>HINT: No operator matches the given name and argument type(s). You may
> >>need to add explicit type casts.
> >>tradein_clients=#
> >>
> >>
> >>
> >>
> >
> >
> >
>
>
>

--
-Achilleus

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