Weird ranking results with ts_rank
| От | Javier Ayres |
|---|---|
| Тема | Weird ranking results with ts_rank |
| Дата | |
| Msg-id | CAC1P-g1YPwVK9ggiRLq=MvGeMp=ciSCsGTnM3L__rWExWTLUdQ@mail.gmail.com обсуждение исходный текст |
| Ответы |
Re: Weird ranking results with ts_rank
|
| Список | pgsql-general |
Hi everybody.
I'm implementing a solution that uses PostgreSQL's full text search capabilities and I have come across a particular set of results for ts_rank that don't seem to make sense according to the documentation. I have tried the following queries in PostgreSQL 10, 11 and 12.
In both cases only the word "box" is matching, but adding a non-matching word with OR to the query increases the ranking. If I keep adding more non-matching words with OR the ranking starts to decrease again, but I would imagine that the second option should have the highest score and it would start decreasing from there the more non-matching words I add.
Is there something I'm not understanding?
Thanks.
postgres=# select ts_rank(to_tsvector('search for a text box'), to_tsquery('circle | lot <-> box'));
ts_rank
-------------
0.020264236
(1 row)
postgres=# select ts_rank(to_tsvector('search for a text box'), to_tsquery('lot <-> box'));
ts_rank
---------
1e-20
(1 row)
--
ts_rank
-------------
0.020264236
(1 row)
postgres=# select ts_rank(to_tsvector('search for a text box'), to_tsquery('lot <-> box'));
ts_rank
---------
1e-20
(1 row)
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