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 = 'CHINA' and n2.n_name = 'ETHIOPIA') or (n1.n_name = 'ETHIOPIA' and n2.n_name = 'CHINA') ) 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=1988699.70..1988707.34 rows=3056 width=64) (actual time=25247.288..25247.290 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=5040923 read=528179 dirtied=170 written=9630 -> HashAggregate (cost=1988476.95..1988522.79 rows=3056 width=64) (actual time=25247.196..25247.205 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=5040915 read=528179 dirtied=170 written=9630 -> Hash Join (cost=62340.37..1987561.62 rows=61022 width=64) (actual time=987.822..25155.329 rows=57997 loops=1) Hash Cond: (lineitem.l_suppkey = supplier.s_suppkey) Join Filter: (((n1.n_name = 'CHINA'::bpchar) AND (n2.n_name = 'ETHIOPIA'::bpchar)) OR ((n1.n_name = 'ETHIOPIA'::bpchar) AND (n2.n_name = 'CHINA'::bpchar))) Rows Removed by Join Filter: 58157 Buffers: shared hit=5040915 read=528179 dirtied=170 written=9630 -> Nested Loop (cost=58604.97..1975676.40 rows=1466303 width=42) (actual time=940.312..24157.522 rows=1468459 loops=1) Buffers: shared hit=5038732 read=528179 dirtied=170 written=9630 -> Hash Join (cost=58604.40..534837.31 rows=1211997 width=30) (actual time=940.157..13274.074 rows=1208318 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=184272 read=106808 dirtied=170 written=3821 -> Seq Scan on orders (cost=0.00..407300.59 rows=15149959 width=8) (actual time=0.010..3901.488 rows=15000000 loops=1) Buffers: shared hit=184269 read=71532 dirtied=170 written=1536 -> Hash (cost=57104.40..57104.40 rows=120000 width=30) (actual time=939.419..939.419 rows=120536 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 8323kB Buffers: shared hit=3 read=35276 written=2285 -> Hash Join (cost=1.40..57104.40 rows=120000 width=30) (actual time=0.050..893.021 rows=120536 loops=1) Hash Cond: (customer.c_nationkey = n2.n_nationkey) Buffers: shared hit=3 read=35276 written=2285 -> Seq Scan on customer (cost=0.00..50278.00 rows=1500000 width=8) (actual time=0.004..658.897 rows=1500000 loops=1) Buffers: shared hit=2 read=35276 written=2285 -> Hash (cost=1.38..1.38 rows=2 width=30) (actual time=0.030..0.030 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=0.014..0.019 rows=2 loops=1) Filter: ((n_name = 'ETHIOPIA'::bpchar) OR (n_name = 'CHINA'::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..1.15 rows=4 width=20) (actual time=0.008..0.008 rows=1 loops=1208318) Index Cond: ((l_orderkey = orders.o_orderkey) AND (l_shipdate >= '1995-01-01'::date) AND (l_shipdate <= '1996-12-31'::date)) Buffers: shared hit=4854460 read=421371 written=5809 -> Hash (cost=3635.40..3635.40 rows=8000 width=30) (actual time=47.236..47.236 rows=7933 loops=1) Buckets: 8192 Batches: 1 Memory Usage: 545kB Buffers: shared hit=2180 -> Hash Join (cost=1.40..3635.40 rows=8000 width=30) (actual time=0.043..45.017 rows=7933 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=0.008..28.857 rows=100000 loops=1) Buffers: shared hit=2179 -> Hash (cost=1.38..1.38 rows=2 width=30) (actual time=0.020..0.020 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=0.008..0.014 rows=2 loops=1) Filter: ((n_name = 'CHINA'::bpchar) OR (n_name = 'ETHIOPIA'::bpchar)) Rows Removed by Filter: 23 Buffers: shared hit=1 Planning time: 6.270 ms Execution time: 25247.891 ms (54 rows) COMMIT; COMMIT