I have this query that is not picking the right index unless I hard code dates: SELECT "topics".* FROM "topics" WHERE topics.last_unread_at >= '2017-05-11 20:56:24' "Index Scan using index_topics_on_last_unread_at on topics (cost=0.41..8.43 rows=1 width=725) (actual time=0.005..0.065 rows=5 loops=1)" " Index Cond: (last_unread_at >= '2017-05-11 20:56:24'::timestamp without time zone)" "Planning time: 0.136 ms" "Execution time: 0.087 ms" SELECT "topics".* FROM "topics" WHERE topics.last_unread_at >= (select first_topic_unread_at from user_stats us where us.user_id = 1) "Seq Scan on topics (cost=8.30..24030.12 rows=20555 width=725) (actual time=3.186..59.636 rows=5 loops=1)" " Filter: (last_unread_at >= $0)" " Rows Removed by Filter: 61660" " InitPlan 1 (returns $0)" " -> Index Scan using user_stats_pkey on user_stats us (cost=0.29..8.30 rows=1 width=8) (actual time=0.008..0.009 rows=1 loops=1)" " Index Cond: (user_id = 1)" "Planning time: 0.147 ms" "Execution time: 59.671 ms" select first_topic_unread_at from user_stats us where us.user_id = 1 "2017-05-11 20:56:24.842356" The results here simply do not make sense to me, should I be piping dates in here to avoid this issue and running 2 queries instead of 1? -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
