Re: n-gram search function - Mailing list pgsql-hackers

From Oleg Bartunov
Subject Re: n-gram search function
Date
Msg-id Pine.LNX.4.64.0702191805000.400@sn.sai.msu.ru
Whole thread Raw
In response to Re: n-gram search function  ("Guillaume Smet" <guillaume.smet@gmail.com>)
Responses Re: n-gram search function  ("Guillaume Smet" <guillaume.smet@gmail.com>)
List pgsql-hackers
On Mon, 19 Feb 2007, Guillaume Smet wrote:

> On 2/19/07, Oleg Bartunov <oleg@sai.msu.su> wrote:
>> pg_trgm was developed for spelling corrrection and there is a threshold of
>> similarity, which is 0.3 by default. Readme explains what does it means.
>
> Yes, I read it.
>
>> Similarity could be very low, since you didn't make separate column and 
>> length
>> of the full string is used to normalize similarity.
>
> Yep, that's probably my problem. Ignored records are a bit longer than
> the others.
>
> I tried the tip in README.pg_trgm to generate a table with all the words.
>
> It can do the work in conjunction of tsearch2 and a bit of AJAX to
> suggest the full words to the users. The reason why I was not using
> tsearch2 is that it's sometimes hard to spell location names
> correctly.
>
> The only problem is that it is still quite slow on a 50k rows words
> table but I'll make further tests on a decent server this afternoon.

You need to wait GiN support.

    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


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