On 10/28/2015 12:12 AM, 657985...@qq.com wrote:
Thank you for your reply.
tshow=> explain (analyze, buffers) select count(t.*) from tshow.res_room_weight t,tshow.res_room_info r
tshow-> where t.subcatlg_id=46
tshow-> and t.roomid = r.actorid
tshow-> and r.levels>=0;
http://explain.depesz.com/s/oKN5
shows where the time is spent in that query, but as you say, that one
the timing was fine. there's a lot of time being spent in a seq_scan
of res_room_info.
I would have written that query as the inner join it is, but that
probably won't effect how it's executed.
select ... from tshow.res_room_weight t join tshow.res_room_info r on
(t.roomid = r.actorid) where t.subcatlg_id=46 and r.levels>=0;
--
john r pierce, recycling bits in santa cruz
