Marc Mamin wrote: > - BRIN cost: I've made a silly test, where all distinct values exist in all > BRIN page ranges: > > INSERT into tbrin_1 (cat_id, ....) SELECT s%20, ... FROM > generate_series(1,3000000 )s; > CREATE INDEX cat_brin_1 on tbrin_1 using BRIN (cat_id)with > (pages_per_range=64); > SELECT * from tbrin_1 WHERE cat_id=10; > http://explain.depesz.com/s/9YQR > > There seems to be no "fence" against useless BRIN indexes that would allow > a fallback on a table scan. > But the time overhead remind small :)
Hmm, I guess the costing function for brin could stand some improvement. Clearly we're not covering all bases. -- Álvaro Herrera http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
