postgresql pg_trgm.word_similarity_threshold decreasing

Question

SET pg_trgm.word_similarity_threshold TO 0.2; lowers the threshold for current session but does not do it for database. I need to lower the threshold for supporting spelling mistakes.

Answer 1

Like the documentation says, there are two options to change the value globally (for the whole database cluster):

1. Add the parameter to postgresql.conf and run pg_ctl reload.

2. Run ALTER SYSTEM SET pg_trgm.word_similarity_threshold = 0.2; and SELECT pg_reload_conf();.

If you want to change it for a specific database, you can use

ALTER DATABASE mydb SET pg_trgm.word_similarity_threshold = 0.2;

The new setting will then be effective for all new connections.