BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select sum(l_extendedprice) / 7.0 as avg_yearly from lineitem, part where p_partkey = l_partkey and p_brand = 'Brand#51' and p_container = 'MED CASE' and l_quantity < ( select 0.2 * avg(l_quantity) from lineitem where l_partkey = p_partkey ); QUERY PLAN -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Aggregate (cost=356788.65..356788.67 rows=1 width=4) (actual time=895.161..895.161 rows=1 loops=1) Buffers: shared hit=53236 read=31339 dirtied=196 written=24 -> Nested Loop (cost=130.19..356738.02 rows=20255 width=4) (actual time=0.841..894.084 rows=5486 loops=1) Buffers: shared hit=53236 read=31339 dirtied=196 written=24 -> Index Only Scan using part_p_container_p_brand_p_partkey_idx on part (cost=0.43..7930.09 rows=2008 width=4) (actual time=0.140..37.887 rows=2009 loops=1) Index Cond: ((p_container = 'MED CASE'::bpchar) AND (p_brand = 'Brand#51'::bpchar)) Heap Fetches: 2009 Buffers: shared hit=73 read=1908 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=129.76..173.61 rows=10 width=12) (actual time=0.006..0.008 rows=3 loops=2009) Index Cond: ((l_partkey = part.p_partkey) AND (l_quantity < (SubPlan 1))) Buffers: shared hit=13577 SubPlan 1 -> Aggregate (cost=129.19..129.20 rows=1 width=4) (actual time=0.414..0.414 rows=1 loops=2009) Buffers: shared hit=39586 read=29431 dirtied=196 written=24 -> Index Only Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem lineitem_1 (cost=0.56..129.11 rows=31 width=4) (actual time=0.043..0.405 rows=30 loops=2009) Index Cond: (l_partkey = part.p_partkey) Heap Fetches: 60691 Buffers: shared hit=39586 read=29431 dirtied=196 written=24 SubPlan 1 -> Aggregate (cost=129.19..129.20 rows=1 width=4) (actual time=0.414..0.414 rows=1 loops=2009) Buffers: shared hit=39586 read=29431 dirtied=196 written=24 -> Index Only Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem lineitem_1 (cost=0.56..129.11 rows=31 width=4) (actual time=0.043..0.405 rows=30 loops=2009) Index Cond: (l_partkey = part.p_partkey) Heap Fetches: 60691 Buffers: shared hit=39586 read=29431 dirtied=196 written=24 Planning time: 3.538 ms Execution time: 895.342 ms (27 rows) COMMIT; COMMIT