BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select supp_nation, cust_nation, l_year, sum(volume) as revenue from ( select n1.n_name as supp_nation, n2.n_name as cust_nation, extract(year from l_shipdate) as l_year, l_extendedprice * (1 - l_discount) as volume from supplier, lineitem, orders, customer, nation n1, nation n2 where s_suppkey = l_suppkey and o_orderkey = l_orderkey and c_custkey = o_custkey and s_nationkey = n1.n_nationkey and c_nationkey = n2.n_nationkey and ( (n1.n_name = 'ROMANIA' and n2.n_name = 'SAUDI ARABIA') or (n1.n_name = 'SAUDI ARABIA' and n2.n_name = 'ROMANIA') ) and l_shipdate between date '1995-01-01' and date '1996-12-31' ) as shipping group by supp_nation, cust_nation, l_year order by supp_nation, cust_nation, l_year; QUERY PLAN --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- GroupAggregate (cost=2357526.75..2359426.21 rows=58445 width=64) (actual time=93404.422..93430.154 rows=4 loops=1) Buffers: shared hit=767126 read=663586 written=18035 -> Sort (cost=2357526.75..2357672.86 rows=58445 width=64) (actual time=93395.335..93400.719 rows=58664 loops=1) Sort Key: n1.n_name, n2.n_name, (date_part('year'::text, (lineitem.l_shipdate)::timestamp without time zone)) Sort Method: quicksort Memory: 9786kB Buffers: shared hit=767126 read=663586 written=18035 -> Hash Join (cost=895800.40..2352899.43 rows=58445 width=64) (actual time=42687.002..92990.087 rows=58664 loops=1) Hash Cond: ((lineitem.l_suppkey = supplier.s_suppkey) AND (n1.n_nationkey = supplier.s_nationkey)) Buffers: shared hit=767118 read=663586 written=18035 -> Hash Join (cost=891121.40..2318121.45 rows=1461115 width=72) (actual time=42547.777..89325.107 rows=1455607 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=764936 read=663586 written=18035 -> Bitmap Heap Scan on lineitem (cost=387042.02..1730886.34 rows=18278555 width=20) (actual time=15095.707..37587.527 rows=18247629 loops=1) Recheck Cond: ((l_shipdate >= '1995-01-01'::date) AND (l_shipdate <= '1996-12-31'::date)) Buffers: shared hit=453788 read=662103 written=18035 -> Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx (cost=0.00..382472.38 rows=18278555 width=0) (actual time=14334.616..14334.616 rows=18302308 loops=1) Index Cond: ((l_shipdate >= '1995-01-01'::date) AND (l_shipdate <= '1996-12-31'::date)) Buffers: shared hit=3 read=49812 -> Hash (cost=489031.49..489031.49 rows=1203831 width=60) (actual time=27450.990..27450.990 rows=1195017 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 107365kB Buffers: shared hit=311148 read=1483 -> Hash Join (cost=15638.06..489031.49 rows=1203831 width=60) (actual time=625.603..26484.992 rows=1195017 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=311148 read=1483 -> Seq Scan on orders (cost=0.00..404880.36 rows=15059936 width=8) (actual time=0.017..4970.673 rows=15015000 loops=1) Buffers: shared hit=253217 read=1064 -> Hash (cost=14139.26..14139.26 rows=119904 width=60) (actual time=625.449..625.449 rows=119851 loops=1) Buckets: 16384 Batches: 1 Memory Usage: 10768kB Buffers: shared hit=57931 read=419 -> Nested Loop (cost=905.09..14139.26 rows=119904 width=60) (actual time=20.075..383.660 rows=119851 loops=1) Buffers: shared hit=57931 read=419 -> Nested Loop (cost=0.00..28.00 rows=2 width=60) (actual time=0.263..0.379 rows=2 loops=1) Join Filter: (((n1.n_name = 'ROMANIA'::bpchar) AND (n2.n_name = 'SAUDI ARABIA'::bpchar)) OR ((n1.n_name = 'SAUDI ARABIA'::bpchar) AND (n2.n_name = 'ROMANIA'::bpchar))) Rows Removed by Join Filter: 623 Buffers: shared hit=3 -> Index Scan using pk_nation on nation n1 (cost=0.00..12.63 rows=25 width=30) (actual time=0.024..0.048 rows=25 loops=1) Buffers: shared hit=2 -> Materialize (cost=0.00..1.38 rows=25 width=30) (actual time=0.001..0.003 rows=25 loops=25) Buffers: shared hit=1 -> Seq Scan on nation n2 (cost=0.00..1.25 rows=25 width=30) (actual time=0.007..0.010 rows=25 loops=1) Buffers: shared hit=1 -> Bitmap Heap Scan on customer (cost=905.09..6455.63 rows=60000 width=8) (actual time=19.922..175.575 rows=59926 loops=2) Recheck Cond: (c_nationkey = n2.n_nationkey) Buffers: shared hit=57928 read=419 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=13.169..13.169 rows=59926 loops=2) Index Cond: (c_nationkey = n2.n_nationkey) Buffers: shared hit=4 read=332 -> Hash (cost=3179.00..3179.00 rows=100000 width=8) (actual time=138.687..138.687 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=0.015..88.692 rows=100000 loops=1) Buffers: shared hit=2179 Total runtime: 93462.044 ms (53 rows) COMMIT; COMMIT