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 = 'MOZAMBIQUE' and n2.n_name = 'UNITED KINGDOM') or (n1.n_name = 'UNITED KINGDOM' and n2.n_name = 'MOZAMBIQUE') ) 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=2007889.45..2007897.15 rows=3080 width=64) (actual time=26465.429..26465.429 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=5022901 read=513224 dirtied=253 written=11958 -> HashAggregate (cost=2007664.79..2007710.99 rows=3080 width=64) (actual time=26465.346..26465.356 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=5022893 read=513224 dirtied=253 written=11958 -> Hash Join (cost=62340.37..2006747.03 rows=61184 width=64) (actual time=755.660..26379.373 rows=57667 loops=1) Hash Cond: (lineitem.l_suppkey = supplier.s_suppkey) Join Filter: (((n1.n_name = 'MOZAMBIQUE'::bpchar) AND (n2.n_name = 'UNITED KINGDOM'::bpchar)) OR ((n1.n_name = 'UNITED KINGDOM'::bpchar) AND (n2.n_name = 'MOZAMBIQUE'::bpchar))) Rows Removed by Join Filter: 57423 Buffers: shared hit=5022893 read=513224 dirtied=253 written=11958 -> Nested Loop (cost=58604.97..1994834.47 rows=1471711 width=42) (actual time=707.113..25397.502 rows=1458717 loops=1) Buffers: shared hit=5020710 read=513224 dirtied=253 written=11958 -> Hash Join (cost=58604.40..532949.50 rows=1207192 width=30) (actual time=707.059..13151.715 rows=1200969 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=216999 read=73067 dirtied=253 written=2015 -> Seq Scan on orders (cost=0.00..405686.04 rows=15089904 width=8) (actual time=0.010..3999.727 rows=15000000 loops=1) Buffers: shared hit=181818 read=72969 dirtied=253 written=2015 -> Hash (cost=57104.40..57104.40 rows=120000 width=30) (actual time=706.425..706.425 rows=120177 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 8301kB Buffers: shared hit=35181 read=98 -> Hash Join (cost=1.40..57104.40 rows=120000 width=30) (actual time=0.053..666.684 rows=120177 loops=1) Hash Cond: (customer.c_nationkey = n2.n_nationkey) Buffers: shared hit=35181 read=98 -> Seq Scan on customer (cost=0.00..50278.00 rows=1500000 width=8) (actual time=0.011..431.409 rows=1500000 loops=1) Buffers: shared hit=35180 read=98 -> Hash (cost=1.38..1.38 rows=2 width=30) (actual time=0.027..0.027 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=0.017..0.019 rows=2 loops=1) Filter: ((n_name = 'UNITED KINGDOM'::bpchar) OR (n_name = 'MOZAMBIQUE'::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=0.009..0.009 rows=1 loops=1200969) Index Cond: ((l_orderkey = orders.o_orderkey) AND (l_shipdate >= '1995-01-01'::date) AND (l_shipdate <= '1996-12-31'::date)) Buffers: shared hit=4803711 read=440157 written=9943 -> Hash (cost=3635.40..3635.40 rows=8000 width=30) (actual time=48.283..48.283 rows=7897 loops=1) Buckets: 8192 Batches: 1 Memory Usage: 543kB Buffers: shared hit=2180 -> Hash Join (cost=1.40..3635.40 rows=8000 width=30) (actual time=0.042..46.123 rows=7897 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=0.006..29.321 rows=100000 loops=1) Buffers: shared hit=2179 -> Hash (cost=1.38..1.38 rows=2 width=30) (actual time=0.023..0.023 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..0.015 rows=2 loops=1) Filter: ((n_name = 'MOZAMBIQUE'::bpchar) OR (n_name = 'UNITED KINGDOM'::bpchar)) Rows Removed by Filter: 23 Buffers: shared hit=1 Planning time: 5.508 ms Execution time: 26465.980 ms (54 rows) COMMIT; COMMIT