DROP TABLE toto;
CREATE TABLE toto (id integer, h hstore);
INSERT INTO toto SELECT cast( random() * 1000 as integer) as i,
                        hstore(cast(cast( random() * 1000 as integer) as text), 'a')
                 FROM generate_series(1,10000);
CREATE INDEX idx_toto_h ON toto USING gist(h);
ANALYZE toto;
EXPLAIN SELECT * from toto where h ? '500';