Slow queries Sesql

gistfile1.txt

# 6s
2012-05-15 19:59:43 CEST LOG:  duration: 6309.370 ms  statement: SELECT classname, id
	FROM sesql_default
	WHERE (workflow_state = 20) AND (fulltext_tsv @@ plainto_tsquery('public.lem_french', E'ayrault ')) AND (classname IN (E'Article',E'Slideshow',E'Media',E'Pointer',E'Chat',E'Forum')) AND (workflow_state = 20) AND (editorial_source IN (20,10)) AND (publication_date >= E'2011-11-17')
	ORDER BY publication_date_time DESC
	LIMIT 1000


# 56s
2012-05-15 19:54:33 CEST LOG:  duration: 56736.021 ms  statement: SELECT classname, id
	FROM sesql_default
	WHERE (workflow_state = 20) AND (fulltext_tsv @@ plainto_tsquery('public.lem_french', E'juge')) AND (classname IN (E'Article',E'Slideshow',E'Media',E'Pointer',E'Chat',E'Forum')) AND (workflow_state = 20) AND (editorial_source IN (20,10)) AND (publication_date >= E'2011-11-17')
	ORDER BY publication_date_time DESC
	LIMIT 1000

# 25s
2012-05-15 20:17:59 CEST LOG:  duration: 25753.959 ms  statement: SELECT classname, id
	FROM sesql_default
	WHERE (workflow_state = 20) AND (fulltext_tsv @@ plainto_tsquery('public.lem_french', E'grand paris')) AND (classname IN (E'Article',E'Slideshow',E'Media',E'Pointer',E'Chat',E'Forum')) AND (workflow_state = 20) AND (editorial_source IN (20,10)) AND (publication_date >= E'2011-11-17')
	ORDER BY publication_date_time DESC
	LIMIT 1000