PostGresqL full-text Search characters problème

Question

Well my problem is : I am using the full-text search of postgresql with a french dictionnary, and I have in my data base some descriptions that contains names with one character for exemple : Amphi 'A' , Amphi 'C, Amphi 'D' ... well, for that, when I use tsvector auto creation trigger, somme names don't appear, for Amphi A I got 'amphi':1 'a':2 but for Amphi 'C' is 'amphi':1 without the it's name.

please help me :D

Answer 1

That's because f.ex. C and D considered to be stop words in the french dictionary:

SELECT to_tsvector('french', 'Amphi A'); -- 'a':2 'amphi':1
SELECT to_tsvector('french', 'Amphi C'); -- 'amphi':1

You can create a custom dictionary (& a configuration for that) without stop words by:

CREATE TEXT SEARCH DICTIONARY french_stem_nostop(
    TEMPLATE = snowball,
    LANGUAGE = 'french'
);

CREATE TEXT SEARCH CONFIGURATION french_nostop(COPY = french);
ALTER TEXT SEARCH CONFIGURATION french_nostop
    ALTER MAPPING FOR asciihword WITH french_stem_nostop;
ALTER TEXT SEARCH CONFIGURATION french_nostop
    ALTER MAPPING FOR asciiword WITH french_stem_nostop;
ALTER TEXT SEARCH CONFIGURATION french_nostop
    ALTER MAPPING FOR hword WITH french_stem_nostop;
ALTER TEXT SEARCH CONFIGURATION french_nostop
    ALTER MAPPING FOR hword_asciipart WITH french_stem_nostop;
ALTER TEXT SEARCH CONFIGURATION french_nostop
    ALTER MAPPING FOR hword_part WITH french_stem_nostop;

SELECT to_tsvector('french_nostop', 'Amphi C'); -- 'amphi':1 'c':2