BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select n_name, sum(l_extendedprice * (1 - l_discount)) as revenue from customer, orders, lineitem, supplier, nation, region where c_custkey = o_custkey and l_orderkey = o_orderkey and l_suppkey = s_suppkey and c_nationkey = s_nationkey and s_nationkey = n_nationkey and n_regionkey = r_regionkey and r_name = 'EUROPE' and o_orderdate >= date '1995-01-01' and o_orderdate < date '1995-01-01' + interval '1 year' group by n_name order by revenue desc; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2446747.53..2446747.59 rows=25 width=34) (actual time=94782.637..94782.637 rows=5 loops=1) Sort Key: (sum((lineitem.l_extendedprice * (1::double precision - lineitem.l_discount)))) Sort Method: quicksort Memory: 25kB Buffers: shared hit=1124691 read=362853 written=6261 -> HashAggregate (cost=2446746.70..2446746.95 rows=25 width=34) (actual time=94782.528..94782.532 rows=5 loops=1) Buffers: shared hit=1124688 read=362853 written=6261 -> Hash Join (cost=403487.41..2446006.43 rows=74027 width=34) (actual time=16640.017..94564.166 rows=72584 loops=1) Hash Cond: ((lineitem.l_suppkey = supplier.s_suppkey) AND (customer.c_nationkey = supplier.s_nationkey)) Buffers: shared hit=1124688 read=362853 written=6261 -> Hash Join (cost=398808.41..2403574.18 rows=1850649 width=46) (actual time=16497.236..89793.350 rows=1822081 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=1122506 read=362853 written=6261 -> Seq Scan on lineitem (cost=0.00..1683116.52 rows=60628552 width=16) (actual time=0.059..27981.059 rows=59984384 loops=1) Buffers: shared hit=783776 read=293055 -> Hash (cost=393027.87..393027.87 rows=462443 width=38) (actual time=16496.212..16496.212 rows=455566 loops=1) Buckets: 65536 Batches: 1 Memory Usage: 32032kB Buffers: shared hit=338730 read=69798 written=6261 -> Hash Join (cost=89248.41..393027.87 rows=462443 width=38) (actual time=5180.305..16016.646 rows=455566 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=338730 read=69798 written=6261 -> Bitmap Heap Scan on orders (cost=50206.19..340690.42 rows=2312215 width=8) (actual time=2151.304..6729.752 rows=2275277 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate < '1996-01-01 00:00:00'::timestamp without time zone)) Buffers: shared hit=228658 read=33692 written=2686 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..49628.14 rows=2312215 width=0) (actual time=1957.639..1957.639 rows=2299709 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate < '1996-01-01 00:00:00'::timestamp without time zone)) Buffers: shared hit=320 read=6249 written=738 -> Hash (cost=35292.22..35292.22 rows=300000 width=38) (actual time=3028.533..3028.533 rows=300963 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 21162kB Buffers: shared hit=110072 read=36106 written=3575 -> Nested Loop (cost=905.09..35292.22 rows=300000 width=38) (actual time=32.992..2785.712 rows=300963 loops=1) Buffers: shared hit=110072 read=36106 written=3575 -> Nested Loop (cost=0.00..14.07 rows=5 width=30) (actual time=0.068..0.181 rows=5 loops=1) Join Filter: (nation.n_regionkey = region.r_regionkey) Rows Removed by Join Filter: 20 Buffers: shared hit=3 -> Index Scan using pk_nation on nation (cost=0.00..12.63 rows=25 width=34) (actual time=0.014..0.056 rows=25 loops=1) Buffers: shared hit=2 -> Materialize (cost=0.00..1.07 rows=1 width=4) (actual time=0.002..0.002 rows=1 loops=25) Buffers: shared hit=1 -> Seq Scan on region (cost=0.00..1.06 rows=1 width=4) (actual time=0.028..0.029 rows=1 loops=1) Filter: (r_name = 'EUROPE'::bpchar) Rows Removed by Filter: 4 Buffers: shared hit=1 -> Bitmap Heap Scan on customer (cost=905.09..6455.63 rows=60000 width=8) (actual time=34.735..530.682 rows=60193 loops=5) Recheck Cond: (c_nationkey = nation.n_nationkey) Buffers: shared hit=110069 read=36106 written=3575 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=24.297..24.297 rows=60193 loops=5) Index Cond: (c_nationkey = nation.n_nationkey) Buffers: shared hit=6 read=833 written=87 -> Hash (cost=3179.00..3179.00 rows=100000 width=8) (actual time=139.621..139.621 rows=100000 loops=1) Buckets: 16384 Batches: 1 Memory Usage: 3907kB Buffers: shared hit=2179 -> Seq Scan on supplier (cost=0.00..3179.00 rows=100000 width=8) (actual time=0.019..93.235 rows=100000 loops=1) Buffers: shared hit=2179 Total runtime: 94805.447 ms (55 rows) COMMIT; COMMIT