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

Reply via email to