Re: TS: Limited cover density ranking

----- Цитат от karavelov@mail.bg, на 27.01.2012 в 18:48 ----- <br /><br />> ----- Цитат от Sushant Sinha
(sushant354@gmail.com),на 27.01.2012 в 18:32 ----- <br />> <br />>> The rank counts 1/coversize. So bigger
coverswill not have much impact <br />>> anyway. What is the need of the patch? <br />>> <br />>>
-Sushant.<br />>> <br />> <br />> If you want to find only combinations of words that are close one to
another,with the patch you could use something as: <br />> <br />> WITH a AS (SELECT to_tsvector('a b c d e g h i
jk') AS vec, to_tsquery('a&d') AS query) <br />> SELECT * FROM a WHERE vec @@ query AND
ts_rank_cd(3,vec,query)>0;<br />> <br /><br />Another example, if you want to match 'b c d' only, you could use:
<br/><br />WITH A AS (SELECT to_tsvector('a b c d e g h i j k') AS vec, to_tsquery('b&c&d') AS query) <br
/>SELECT* FROM A WHERE vec @@ query AND ts_rank_cd(2,vec,query)>0; <br /><br />The catch is that it will match also
'bd c', 'd c b', 'd b c', 'c d b' and 'd b d', so it is not a <br />replacement for exact phrase match but something
thatI find useful <br /><br />-- <br />Luben Karavelov