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 = 'ETHIOPIA') or (n1.n_name = 'ETHIOPIA' 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 ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- GroupAggregate (cost=2363382.09..2365289.19 rows=58680 width=64) (actual time=100936.352..100962.004 rows=4 loops=1) Buffers: shared hit=536434 read=897114 dirtied=704 written=19840 -> Sort (cost=2363382.09..2363528.79 rows=58680 width=64) (actual time=100927.029..100932.742 rows=57578 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: 9633kB Buffers: shared hit=536434 read=897114 dirtied=704 written=19840 -> Hash Join (cost=897940.28..2358734.46 rows=58680 width=64) (actual time=49783.719..100582.451 rows=57578 loops=1) Hash Cond: ((lineitem.l_suppkey = supplier.s_suppkey) AND (n1.n_nationkey = supplier.s_nationkey)) Buffers: shared hit=536426 read=897114 dirtied=704 written=19840 -> Hash Join (cost=893261.28..2323835.06 rows=1467010 width=72) (actual time=49641.952..97197.950 rows=1465820 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=534244 read=897114 dirtied=704 written=19840 -> Bitmap Heap Scan on lineitem (cost=388209.93..1735292.48 rows=18352303 width=20) (actual time=15719.784..40337.389 rows=18247594 loops=1) Recheck Cond: ((l_shipdate >= '1995-01-01'::date) AND (l_shipdate <= '1996-12-31'::date)) Buffers: shared hit=238966 read=879049 dirtied=704 written=19840 -> Bitmap Index Scan on lineitem_l_shipdate_l_suppkey__idx (cost=0.00..383621.86 rows=18352303 width=0) (actual time=15023.471..15023.471 rows=18338343 loops=1) Index Cond: ((l_shipdate >= '1995-01-01'::date) AND (l_shipdate <= '1996-12-31'::date)) Buffers: shared hit=2 read=49813 written=25 -> Hash (cost=489973.51..489973.51 rows=1206227 width=60) (actual time=33920.880..33920.880 rows=1205087 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 108270kB Buffers: shared hit=295278 read=18065 -> Hash Join (cost=15638.06..489973.51 rows=1206227 width=60) (actual time=1403.270..32822.771 rows=1205087 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=295278 read=18065 -> Seq Scan on orders (cost=0.00..405686.04 rows=15089904 width=8) (actual time=0.018..5636.055 rows=15015000 loops=1) Buffers: shared hit=253862 read=925 -> Hash (cost=14139.26..14139.26 rows=119904 width=60) (actual time=1403.051..1403.051 rows=120267 loops=1) Buckets: 16384 Batches: 1 Memory Usage: 10806kB Buffers: shared hit=41416 read=17140 -> Nested Loop (cost=905.09..14139.26 rows=119904 width=60) (actual time=21.843..1311.801 rows=120267 loops=1) Buffers: shared hit=41416 read=17140 -> Nested Loop (cost=0.00..28.00 rows=2 width=60) (actual time=0.124..0.442 rows=2 loops=1) Join Filter: (((n1.n_name = 'MOZAMBIQUE'::bpchar) AND (n2.n_name = 'ETHIOPIA'::bpchar)) OR ((n1.n_name = 'ETHIOPIA'::bpchar) AND (n2.n_name = 'MOZAMBIQUE'::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=0.019..0.046 rows=25 loops=1) Buffers: shared hit=2 -> Materialize (cost=0.00..1.38 rows=25 width=30) (actual time=0.001..0.005 rows=25 loops=25) Buffers: shared hit=1 -> Seq Scan on nation n2 (cost=0.00..1.25 rows=25 width=30) (actual time=0.005..0.011 rows=25 loops=1) Buffers: shared hit=1 -> Bitmap Heap Scan on customer (cost=905.09..6455.63 rows=60000 width=8) (actual time=30.870..633.731 rows=60134 loops=2) Recheck Cond: (c_nationkey = n2.n_nationkey) Buffers: shared hit=41413 read=17140 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=21.707..21.707 rows=60134 loops=2) Index Cond: (c_nationkey = n2.n_nationkey) Buffers: shared hit=1 read=334 -> Hash (cost=3179.00..3179.00 rows=100000 width=8) (actual time=140.336..140.336 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=0.009..95.348 rows=100000 loops=1) Buffers: shared hit=2179 Total runtime: 100996.327 ms (53 rows) COMMIT; COMMIT