tsvector as a column not updated automatically in postgresql - postgresql

Question

Hi postgresql experts,
I have already searched my problem, some of them seem relevant but actually not the same. I apologize first if there is a dup.
I am doing a text search with postgresql. Since I cant change the already defined sql files (limitations from the project), all the updates or changes need to be done in a new file to alter the previous definition. In order to make it clear, I will list all the code I have which are related to the table which am doing full text search. I will list the codes in their execute order.
My problem is, whenever I insert a row to mytable, the search_vector is not updated automatically. Only when I execute the 5th sql after the insertion, the search_vector is updated according to its definition. Wired thing is that, even though I change the code in 3th or 4th sql to change the search_vector definition, eg. to make
search_vector = to_tsvector('english', name);
the insertion after that is still not updating their search_vector, still keeps the same as the previous definition.
1. created a table:
CREATE TABLE mytable {
id VARCHAR(20) PRIMARY KEY,
name VARCHAR NOT NULL,
label VARCHAR,
color VARCHAR NOT NULL
};
2. update the search_vector as a column and also use trigger and index:
BEGIN;
DROP TRIGGER IF EXISTS mytable_search_vector_trigger ON mytable;
DROP INDEX IF EXISTS search_vector_index;
ALTER TABLE mytable DROP COLUMN IF EXISTS search_vector;
ALTER TABLE mytable ADD COLUMN search_vector tsvector;
UPDATE mytable
SET search_vector = to_tsvector('english', id || ' ' || name || ' ' ||
coalesce(label, ''));
CREATE INDEX search_vector_index ON opportunity USING gin(search_vector);
CREATE TRIGGER mytable_search_vector_trigger BEFORE INSERT OR UPDATE ON
mytable
FOR EACH ROW EXECUTE PROCEDURE tsvector_update_trigger(search_vector,
'pg_catalog.english', id, name, label);
ANALYZE mytable;
COMMIT;
3. add another column and update the search_vector and the trigger:
BEGIN;
ALTER TABLE mytable ADD COLUMN product_number CHAR(6);
DROP TRIGGER IF EXISTS mytable_search_vector_trigger ON mytable;
DROP INDEX IF EXISTS search_vector_index;
ALTER TABLE mytable DROP COLUMN IF EXISTS search_vector;
ALTER TABLE mytable ADD COLUMN search_vector tsvector;
UPDATE mytable
SET search_vector = to_tsvector('english', id || ' ' || name || ' ' ||
product_number || ' ' || coalesce(label, ''));
CREATE INDEX search_vector_index ON mytable USING gin(search_vector);
CREATE TRIGGER mytable_search_vector_trigger
BEFORE INSERT OR UPDATE ON mytable
FOR EACH ROW EXECUTE PROCEDURE tsvector_update_trigger(search_vector,
'pg_catalog.english', id, name, product_number, label);
ANALYZE mytable;
COMMIT;
4. change the primary key type:
BEGIN;
ALTER TABLE mytable
ALTER COLUMN id SET DATA TYPE CHAR(18);
COMMIT;
5. update the search_vector:
BEGIN;
DROP TRIGGER IF EXISTS mytable_search_vector_trigger ON mytable;
DROP INDEX IF EXISTS search_vector_index;
CREATE TRIGGER mytable_search_vector_trigger BEFORE INSERT OR UPDATE
ON mytable FOR EACH ROW EXECUTE PROCEDURE
tsvector_update_trigger(search_vector, 'pg_catalog.english', id, name,
product_number, label);
UPDATE mytable
SET search_vector = to_tsvector('english', substring(id from 1 for 15) || ' '
|| id || ' ' || name || ' ' || coalesce(product_number, '') ||
coalesce(application_name, ''))
WHERE search_vector IS NOT NULL; -- tried delete this, but not working, also tried to change the 'english' to 'pg_catalog.english', not working as well.
CREATE INDEX search_vector_idx ON mytable USING gin(search_vector);
ANALYZE mytable;
COMMIT;
Thanks in advance for any advice.