Re: Rank based on the number of matching OR fields?
| От | Joel Hoffman |
|---|---|
| Тема | Re: Rank based on the number of matching OR fields? |
| Дата | |
| Msg-id | CAEF8rJv9XG=3F3C9PZMqqPSqALmrX3Rqtx+1H=o7d9KPnomZgA@mail.gmail.com обсуждение исходный текст |
| Ответ на | Rank based on the number of matching OR fields? ("W. Matthew Wilson" <matt@tplus1.com>) |
| Список | pgsql-general |
If you're easily able to do it, (i.e. you're building rather than receiving the query), you could rank them by the conjunction of the search terms first:
ORDER BY ts_rank(vector, to_tsquery('A & B & C')) desc, ts_rank(vector, to_tsquery('A | B | C')) desc
Or just explicitly order by whether the conjunction matches:
ORDER BY case when to_tsquery('A & B & C') @@ vector then 0 else 1 end, ts_rank(vector, to_tsquery('A | B | C')) desc
I think either of these would have the property you want, but I don't know how they would otherwise affect the quality of the ranking. You should set up a test group of documents and make sure your mechanism ranks that group properly on test queries.
Joel
On Tue, Sep 25, 2012 at 11:16 AM, W. Matthew Wilson <matt@tplus1.com> wrote:
I want to run a query like to_tsquery("A | B | C") and then rank the
results so that if a document contained A, B, and C, then it would
rank above a document that just had some subset.
How would I do such a thing?
--
W. Matthew Wilson
matt@tplus1.com
http://tplus1.com
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