On Thu, 31 May 2007, Erwin Moller wrote:
Hi all,
I installed TSEARCH2 on Postgres8.1 (Debian).
It runs all fine.
I have 2 tables indexed, and created triggers to keep the vectorcolumns
up
to date.
However, the text I indexed is a mix of Dutch and English and German.
The default stemmingprocess is an annoyance for me.
I would like to disable it.
I found out that using 'simple' instead of 'default' when using
to_tsvector() does excactly that, but I don't know how to change my
triggers and indexes to keep doing the same (using 'simple').
My TSEARCH2 and trigger-skills are developing, but I lack the confidence
to
change thing on the site (which is live), so I thought I check in here.
I have a table named tblvacature, that contains a bunch of columns that
need
to be indexed by TSEARCH.
This is what I did (and it works, except for the fact I want to disable
stemming)
1) ALTER TABLE tblvacature ADD COLUMN idxFTI tsvector;
2) UPDATE tblvacature SET idxFTI=to_tsvector('simple',
coalesce(title,'') ||' '||
coalesce(shortintro,'') ||' '||
coalesce(werkgever,'') ||' '||
coalesce(vacaturesteller,'') ||' '||
coalesce(standplaats,'') ||' '||
coalesce(divafdelingwerkgever,'') );
3) VACUUM FULL ANALYZE;
4) CREATE INDEX idxFTIvacture_idx ON tblvacature USING gist(idxFTI);
5) VACUUM FULL ANALYZE;
6) CREATE TRIGGER tsvectorupdate_vacature BEFORE UPDATE OR INSERT ON
tblvacature FOR EACH ROW EXECUTE
PROCEDURE tsearch2(idxFTI, title, shortintro, werkgever,
vacaturesteller,
standplaats, divafdelingwerkgever);
Step 2 worked fine: no stemming.
But how do I cange my step6 (trigger) so it keeps using 'simple'?
Or do I have to change the index itself (step4) too? Or both?
Please advise.
tsearch trigger is just an example, you could write your own function !
for example,
create function my_update() returns trigger as
$$
BEGIN
NEW.idxFTI=to_tsvector('simple',
coalesce(title,'') ||' '||
coalesce(shortintro,'') ||' '||
coalesce(werkgever,'') ||' '||
coalesce(vacaturesteller,'') ||' '||
coalesce(standplaats,'') ||' '||
coalesce(divafdelingwerkgever,'') );
RETURN NEW;
END;
$$
language plpgsql;
btw, why do you don't use setweight() function to assign different weights to
the different attributes ?
Thanks for your time.
Regards,
Erwin Moller
-----------------------
PS: This is my first posting to pgsql-general: if I screw something up,
please let me know.
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Regards,
Oleg
_____________________________________________________________
Oleg Bartunov, Research Scientist, Head of AstroNet (www.astronet.ru),
Sternberg Astronomical Institute, Moscow University, Russia
Internet: [EMAIL PROTECTED], http://www.sai.msu.su/~megera/
phone: +007(495)939-16-83, +007(495)939-23-83
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