PostgreSQL 7.4 Manual Example (Continued)

SELECT file, title, chapter, headline(body, to_tsquery('concurrency & control')),
	rank(ts_vec, to_tsquery('concurrency & control'))
FROM postgresql_manual
WHERE ts_vec @@ to_tsquery('concurrency & control')
ORDER BY rank(ts_vec, to_tsquery('concurrency & control'))
DESC LIMIT 3;

-[ RECORD 1 ]-------------------------------------------------------------------------------
file     | mvcc.html
title    | Concurrency Control
chapter  | 12
headline | concurrency control, PostgreSQL maintains data consistency by using 
           a multiversion model (Multiversion Concurrency Control, MVCC
rank     | 0.433306
-[ RECORD 2 ]--------------------------------------------------------------------------------
file     | release-6-5.html
title    | Release 6.5
chapter  |
headline | concurrency control(MVCC) This removes our old table-level locking, 
           and replaces it with a locking
rank     | 0.268841
-[ RECORD 3 ]--------------------------------------------------------------------------------
file     | transaction-iso.html
title    | Transaction Isolation
chapter  | 12
headline | Concurrency Control Fast Forward Next 12.2. Transaction Isolation The 
           SQL standard defines four levels of transaction
rank     | 0.188385