TSEARCH2: disable stemming in indexes and triggers - Mailing list pgsql-general

From Erwin Moller
Subject TSEARCH2: disable stemming in indexes and triggers
Date
Msg-id 1180609279.22968.3291.camel@Willow
Whole thread Raw
Responses Re: TSEARCH2: disable stemming in indexes and triggers
Re: TSEARCH2: disable stemming in indexes and triggers
List pgsql-general
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.


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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