Does update match trigger?

gistfile1.txt

PostgreSQL 9.1.4 on x86_64-apple-darwin11.3.1, compiled by Apple clang version 3.1 (tags/Apple/clang-318.0.61) (based on LLVM 3.1svn), 64-bit

ALTER TABLE users ADD COLUMN tsv tsvector;
UPDATE users SET tsv = (to_tsvector('english', coalesce("users"."email"::text, '')) || 
        to_tsvector('english', coalesce("users"."username"::text, '')) || 
        to_tsvector('english', coalesce("users"."first_name"::text, '')) || 
        to_tsvector('english', coalesce("users"."last_name"::text, '')));


(is this trigger the same as the update above, or do I need my own function?)
CREATE TRIGGER tsvectorupdate BEFORE INSERT OR UPDATE
  ON users FOR EACH ROW EXECUTE PROCEDURE
  tsvector_update_trigger(tsv, 'pg_catalog.english', email, username, first_name, last_name);


Users table:

      Column      |            Type             |                     Modifiers                      
------------------+-----------------------------+----------------------------------------------------
 id               | integer                     | not null default nextval('users_id_seq'::regclass)
 first_name       | character varying(255)      | 
 last_name        | character varying(255)      | 
 email            | character varying(255)      | 
 username         | character varying(255)      | 
 tsv              | tsvector                    |