BM25 scoring is not enabled for term set queries. As a result, the scores returned may not be accurate. This behavior reflects the underlying implementation in Tantivy.
Matches documents containing any term from a specified set. 
SELECT description, rating, category
FROM mock_items
WHERE description @@@ pdb.term_set(ARRAY['shoes', 'keyboard']);
pdb.term_set is equivalent to ORing together multiple pdb.term queries.