=?GBK?B?s8LR47fJ?= <postgresql_2016@xxxxxxx> writes: > postgres=# explain select * from test t1 left join test t2 on t1.b = t2.b and t2.c = 10 where t1.a = 1; > QUERY PLAN > ----------------------------------------------------------------------------- > Nested Loop Left Join (cost=0.85..48.16 rows=7418 width=24) > -> Index Scan using a_idx on test t1 (cost=0.43..8.45 rows=1 width=12) > Index Cond: (a = 1) > -> Index Scan using b_idx on test t2 (cost=0.43..39.64 rows=7 width=12) > Index Cond: (b = t1.b) > Filter: (c = 10) > (6 rows) I tried to reproduce this and could not. What PG version are you running exactly? Can you provide a self-contained example? regards, tom lane
