Re: Rank based on the number of matching OR fields?

[Joel Hoffman <joel.hoffman@xxxxxxxxx>]

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@xxxxxxxxxx> 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@xxxxxxxxxx
http://tplus1.com


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