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 = 'UNITED KINGDOM' and n2.n_name = 'CHINA') or (n1.n_name = 'CHINA' and n2.n_name = 'UNITED KINGDOM') ) 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 ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2013830.67..2013838.34 rows=3067 width=64) (actual time=20927.206..20927.207 rows=4 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: 25kB Buffers: shared hit=5241177 read=315022 dirtied=165 written=7414 -> HashAggregate (cost=2013607.04..2013653.05 rows=3067 width=64) (actual time=20927.118..20927.127 rows=4 loops=1) Group Key: n1.n_name, n2.n_name, date_part('year'::text, (lineitem.l_shipdate)::timestamp without time zone) Buffers: shared hit=5241169 read=315022 dirtied=165 written=7414 -> Hash Join (cost=62340.37..2012689.04 rows=61200 width=64) (actual time=925.365..20841.024 rows=57919 loops=1) Hash Cond: (lineitem.l_suppkey = supplier.s_suppkey) Join Filter: (((n1.n_name = 'UNITED KINGDOM'::bpchar) AND (n2.n_name = 'CHINA'::bpchar)) OR ((n1.n_name = 'CHINA'::bpchar) AND (n2.n_name = 'UNITED KINGDOM'::bpchar))) Rows Removed by Join Filter: 58297 Buffers: shared hit=5241169 read=315022 dirtied=165 written=7414 -> Nested Loop (cost=58604.97..2000779.84 rows=1470626 width=42) (actual time=875.991..20175.404 rows=1462952 loops=1) Buffers: shared hit=5238986 read=315022 dirtied=165 written=7414 -> Hash Join (cost=58604.40..534366.29 rows=1210798 width=30) (actual time=875.927..9977.424 rows=1205488 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=208415 read=82412 dirtied=165 written=1548 -> Seq Scan on orders (cost=0.00..406897.75 rows=15134975 width=8) (actual time=0.009..3797.988 rows=15000000 loops=1) Buffers: shared hit=198034 read=57514 dirtied=165 written=1548 -> Hash (cost=57104.40..57104.40 rows=120000 width=30) (actual time=874.944..874.944 rows=120446 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 8317kB Buffers: shared hit=10381 read=24898 -> Hash Join (cost=1.40..57104.40 rows=120000 width=30) (actual time=0.061..826.718 rows=120446 loops=1) Hash Cond: (customer.c_nationkey = n2.n_nationkey) Buffers: shared hit=10381 read=24898 -> Seq Scan on customer (cost=0.00..50278.00 rows=1500000 width=8) (actual time=0.012..572.948 rows=1500000 loops=1) Buffers: shared hit=10380 read=24898 -> Hash (cost=1.38..1.38 rows=2 width=30) (actual time=0.025..0.025 rows=2 loops=1) Buckets: 1024 Batches: 1 Memory Usage: 9kB Buffers: shared hit=1 -> Seq Scan on nation n2 (cost=0.00..1.38 rows=2 width=30) (actual time=0.016..0.019 rows=2 loops=1) Filter: ((n_name = 'CHINA'::bpchar) OR (n_name = 'UNITED KINGDOM'::bpchar)) Rows Removed by Filter: 23 Buffers: shared hit=1 -> Index Scan using lineitem_l_orderkey_l_linenumber_l_shipdate_idx on lineitem (cost=0.56..1.16 rows=5 width=20) (actual time=0.007..0.008 rows=1 loops=1205488) Index Cond: ((l_orderkey = orders.o_orderkey) AND (l_shipdate >= '1995-01-01'::date) AND (l_shipdate <= '1996-12-31'::date)) Buffers: shared hit=5030571 read=232610 written=5866 -> Hash (cost=3635.40..3635.40 rows=8000 width=30) (actual time=49.127..49.127 rows=7961 loops=1) Buckets: 8192 Batches: 1 Memory Usage: 547kB Buffers: shared hit=2180 -> Hash Join (cost=1.40..3635.40 rows=8000 width=30) (actual time=0.051..46.616 rows=7961 loops=1) Hash Cond: (supplier.s_nationkey = n1.n_nationkey) Buffers: shared hit=2180 -> Seq Scan on supplier (cost=0.00..3179.00 rows=100000 width=8) (actual time=0.009..29.941 rows=100000 loops=1) Buffers: shared hit=2179 -> Hash (cost=1.38..1.38 rows=2 width=30) (actual time=0.021..0.021 rows=2 loops=1) Buckets: 1024 Batches: 1 Memory Usage: 9kB Buffers: shared hit=1 -> Seq Scan on nation n1 (cost=0.00..1.38 rows=2 width=30) (actual time=0.013..0.016 rows=2 loops=1) Filter: ((n_name = 'UNITED KINGDOM'::bpchar) OR (n_name = 'CHINA'::bpchar)) Rows Removed by Filter: 23 Buffers: shared hit=1 Planning time: 6.205 ms Execution time: 20927.754 ms (54 rows) COMMIT; COMMIT