Best way to use PostgreSQL full text search ranking

Question

Following on from this answer I want to know what the best way to use PostgreSQL\'s built-in full text search is if I want to sort by rank, and limit to only matching q

Answer 1

select *
from (
    SELECT
        pictures.id,
        ts_rank_cd(to_tsvector('english', pictures.title), 
        to_tsquery('small dog')) AS score
    FROM pictures
) s
WHERE score > 0
ORDER BY score DESC