Antoine Bajolet <[EMAIL PROTECTED]> writes: > We are using postgresql in a search engine on an intranet handling > throusand of documents. > But we ave a big problem when users use more than two search key.
I think you need to increase the statistics targets for your keywords table --- the estimates of numbers of matching rows are much too small: > -> Index Scan using keyword_pattern_key on keywords > k2 (cost=0.00..3.51 rows=1 width=4) (actual time=0.078..1.887 rows=75 > loops=1) > Index Cond: (((keyword)::text ~>=~ > 'exploitation'::character varying) AND ((keyword)::text ~<~ > 'exploitatioo'::character varying)) > Filter: ((keyword)::text ~~ 'exploitation%'::text) A factor-of-75 error is quite likely to mislead the planner into choosing a bad join plan. BTW, have you looked into using a real full-text-search engine (eg, tsearch2) instead of rolling your own like this? regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org