Re: Behaviour of to_tsquery(stopwords only)

Further tsquery comparison fun:

=> SELECT q.qid, q.query, count(*) FROM doc.documents d, util.queries q 
WHERE d.words @@ q.query AND (q.query::text=$$'tender'$$) GROUP BY 
q.qid, q.query ; qid |  query   | count
-----+----------+------- 195 | 'tender' |   374 248 | 'tender' |   374 257 | 'tender' |   374 332 | 'tender' |   374
401| 'tender' |   374 409 | 'tender' |   374 519 | 'tender' |   374 557 | 'tender' |   374 736 | 'tender' |   374 749 |
'tender'|   374 869 | 'tender' |   374 879 | 'tender' |   374 926 | 'tender' |   374
 
(13 rows)

=> SELECT q.query, count(*) FROM doc.documents d, util.queries q WHERE 
d.words @@ q.query AND (q.query::text=$$'tender'$$) GROUP BY q.query ;  query   | count
----------+------- 'tender' |  1870 'tender' |  1496 'tender' |  1496
(3 rows)


It seems to be that the tsquery is remembering the shape of the original 
query, even though it's been trimmed.


=> SELECT q.query, min(qid), max(qid), count(*) FROM doc.documents d, 
util.queries q WHERE d.words @@ q.query AND (q.query::text=$$'tender'$$) 
GROUP BY q.query ;  query   | min | max | count
----------+-----+-----+------- 'tender' | 736 | 926 |  1870 (5 rows aggregated) 'tender' | 401 | 557 |  1496 (4 rows
aggregated)'tender' | 195 | 332 |  1496 (4 rows aggregated)
 
(3 rows)

=> SELECT * FROM util.queries WHERE qid IN (195,248, 257, 332, 
401,409,519,557,736,749,869,879,926) ORDER BY qid; qid |        words        |  query
-----+---------------------+---------- 195 | can & of & tenders  | 'tender' (3 clauses) 248 | tender & the & this |
'tender'(3 clauses) 257 | have & tender & for | 'tender' (3 clauses) 332 | for & tenders & of  | 'tender' (3 clauses)
401| tender & with       | 'tender' (2 clauses) 409 | tenders & to        | 'tender' (2 clauses) 519 | tender & to
  | 'tender' (2 clauses) 557 | tenders & be        | 'tender' (2 clauses) 736 | tenderer            | 'tender' (1
clause)749 | tender              | 'tender' (1 clause) 869 | tender              | 'tender' (1 clause) 879 | tender
        | 'tender' (1 clause) 926 | tender              | 'tender' (1 clause)
 
(13 rows)

So - is this a bug, feature, "feature"?

--   Richard Huxton  Archonet Ltd