hello -- i have a schema similar to the following
create table foo ( id integer not null, val integer not null, s integer not null, e integer not null ); create index foo_s_idx on foo using btree (s); create index foo_e_idx on foo using btree (e); i want to do queries like select * from foo where 150 between s and e; this usually gives me index or bitmap scans on one of the indices, plus a filter for the other condition. this is not terribly efficient as the table is large (billions of rows), but there should only be a few thousand rows with s < k < e for any k. the data is id, value, interval (s, e), with s < e, and e - s is "small". i am experimenting and would like to see the effect of using a bitmap index "AND" scan using both indices. as far as i can tell, there are no easy ways to force or encourage this -- there are no switches like enable_seqscan and such which force the use of bitmap AND, and i don't know how to tell the query planner about the structure of the data (i don't think this is adequately captured in any of the statistics it generates, i would need multi-column statistics.) any clues? best regards, ben -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
