On most nested loops that I do explain/explain analyze on, the row estimation for the nested-loop itself is a product of the inner nodes of the nested loop. However in this case, I am stumped! explain select era.child_entity from entity_rel era join user_entity ue on ue.entity_id = era.parent_entity and ue.user_id=12345 Nested Loop (cost=0.00..2903.37 rows=29107 width=4) -> Index Only Scan using entity_pk on user_entity ue (cost=0.00..62.68 rows=2 width=4) Index Cond: (user_id = 10954) -> Index Scan using rel_parent on entity_rel era (cost=0.00..1261.85 rows=317 width=8) Index Cond: (parent_entity = ue.entity_id) How can the estimated number of rows for the nested loop node EXCEED the product of the 2 row estimates of the tables being joined? Not only does it exceed it - but it is orders of magnitude greater. Am I missing something obvious here? I an see the nested loop row estimate being LESS but certainly not more. PostgreSQL 9.2.4 on x86_64-pc-solaris2.10, compiled by gcc (GCC) 3.4.3 (csl-sol210-3_4-branch+sol_rpath), 64-bit -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
