------------------------------------------------------------

-- Find the best matching document to the keyword query

-- "washington taxes treasury".

------------------------------------------------------------

-- create a new table q

create table if not exists q ( kw varchar(20) );

insert into q values('washington');

insert into q values('taxes');

insert into q values('treasury');

select max(v) as similarity from (

SELECT A.docid, B.docid as b, SUM(A.count) as v

FROM frequency as A join frequency as B on A.term = B.term

WHERE

A.docid < B.docid

and a.term in (select kw from q) -- ('washington','taxes','treasury')

and b.term in (select kw from q) -- ('washington','taxes','treasury')

-- Since we're limiting ourselves to a specific set of documents,

-- our query is faster

GROUP BY A.docid, B.docid

)

;