On several development servers, this query has returned expected records:
SELECT name, name_tsv FROM vision
WHERE name_tsv @@ plainto_tsquery('Washington Square Park');
name_tsv was originally populated on my dev server with
UPDATE vision SET name_tsv=to_tsvector(name);
and is kept up to date with a trigger.
I have created the same database on an AWS PostgreSQL RDS instance. Both dev and RDS Postgres versions are at 9.3.1. As far as I can tell, pg_catalog on each has the same FTS Configurations, Dictionaries, Parsers, and Templates (default; I haven't messed with anything in here). I cannot access the pg conf file on the RDS instance, of course. On this RDS instance, the above query returns 0 records.
I ran this diagnostic query on both:
SELECT name,
name_tsv,
to_tsvector(name),
plainto_tsquery('Washington Square Park'),
name_tsv @@ plainto_tsquery('Washington Square Park') AS matches_stored_name,
to_tsvector(name) @@ plainto_tsquery('Washington Square Park') AS matches_fresh_tsvector
FROM vision WHERE id_vision = 2977;
The result on the RDS instance is:
"1609: Washington Square Park";"'1609':1 'park':4 'squar':3 'washington':2";"'1609':1 'park':4 'square':3 'washington':2";"'washington' & 'square' & 'park'";f;t
The result on the dev instance is:
"1609: Washington Square Park";"'1609':1 'park':4 'squar':3 'washington':2";"'1609':1 'park':4 'squar':3 'washington':2";"'washington' & 'squar' & 'park'";t;t
It appears from the above that on RDS, to_tsvector() and plainto_tsquery() both seem not to produce the truncated lexeme 'squar' that they do on the dev server (the same no-lexeme pattern happens with other strings). However, I tried running
UPDATE vision SET name_tsv=to_tsvector(name);
on the RDS server, but name_tsv did not change (still = "'1609':1 'park':4 'squar':3 'washington':2").
What can I do on the new RDS server to make the first query return expected records the same way it does on my dev server? I think I just need to make plainto_tsquery('Washington Square Park') normalize tokens to lexemes (e.g. return 'squar' not 'square'), but I can't tell from this how to do that.