EXPLAIN SELECT count(DISTINCT catalog.id) FROM catalog WHERE flag=false; QUERY PLAN ----------------------------------------------------------------------------------------- Aggregate (cost=1615927.27..1615927.28 rows=1 width=8) -> Seq Scan on catalog (cost=0.00..1603214.56 rows=5085084 width=8) Filter: (NOT flag) SELECT pg_size_pretty(pg_relation_size('catalog')); pg_size_pretty ---------------- 9380 MB Nothing else is going on the system, during the query disk reads rise from around 0 to > 100MB/s, so I would assume it should take a couple minutes and it takes ten times longer: Time: 1495549.716 ms What am I missing? -- Michal Politowski -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general