"Mark Liberman" <mliberman@xxxxxxxxxxxxxxxx> wrote > > First run, after a night of inactivity: > > -> Bitmap Index Scan on 1min_events_file_id_begin_idx > (cost=0.00..37.85 rows=3670 width=0) (actual time=313.468..313.468 > rows=11082 > loops=1) > Index Cond: (file_id = 137271) > Total runtime: 313.643 ms > > Second run, after that: > > -> Bitmap Index Scan on 1min_events_file_id_begin_idx > (cost=0.00..37.85 rows=3670 width=0) (actual time=2.106..2.106 rows=11082 > loops=1) > Index Cond: (file_id = 137271) > Total runtime: 2.276 ms It is clear that the first query takes longer time because of the IO time of index 1min_events_file_id_begin_idx (see 313.468 vs. 2.106). I am afraid currently there is no easy solution for this situation, unless you could predicate which part of relation/index your query will use, then you can preload or "warm-up" cache for it. Regards, Qingqing
