The following bug has been logged on the website:
Bug reference: 17468
Logged by: vicreal
Email address: vicreal@yandex.ru
PostgreSQL version: 13.1
Operating system: Debian 10
Description:
Test 1
SELECT ts_rank_cd(to_tsvector('This function calculates the coverage
density'), to_tsquery('function | calculates'), 4); -- 0.1
SELECT ts_rank_cd(to_tsvector('This function calculates the coverage
density'), to_tsquery('function'), 4); -- 0.1
Test 2
SELECT ts_rank_cd(to_tsvector('This function calculates the coverage
density'), to_tsquery('function | calculates'), 1); -- 0.124
SELECT ts_rank_cd(to_tsvector('This function calculates the coverage
density'), to_tsquery('function'), 1); -- 0.062
Test 3
SELECT ts_rank_cd(to_tsvector('This function calculates the coverage
density'), to_tsquery('function | calculates'), 4|1); -- 0.062 (X)
SELECT ts_rank_cd(to_tsvector('This function calculates the coverage
density'), to_tsquery('function'), 4|1); -- 0.062 (Y)
How it should be:
1) In test 3 rank Y should be smaller, than rank X (as in test 2).
2) How get difference ranks Y < X when using normalization variant 4 ?