BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'ALGERIA' then volume else 0 end) / sum(volume) as mkt_share from ( select extract(year from o_orderdate) as o_year, l_extendedprice * (1 - l_discount) as volume, n2.n_name as nation from part, supplier, lineitem, orders, customer, nation n1, nation n2, region where p_partkey = l_partkey and s_suppkey = l_suppkey and l_orderkey = o_orderkey and o_custkey = c_custkey and c_nationkey = n1.n_nationkey and n1.n_regionkey = r_regionkey and r_name = 'AFRICA' and s_nationkey = n2.n_nationkey and o_orderdate between date '1995-01-01' and date '1996-12-31' and p_type = 'LARGE ANODIZED NICKEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2185265.69..2185267.52 rows=733 width=38) (actual time=29592.688..29592.688 rows=2 loops=1) Sort Key: (date_part('year'::text, (orders.o_orderdate)::timestamp without time zone)) Sort Method: quicksort Memory: 25kB Buffers: shared hit=751599 read=253687 dirtied=3449 written=423 -> HashAggregate (cost=2185217.98..2185230.81 rows=733 width=38) (actual time=29592.608..29592.609 rows=2 loops=1) Buffers: shared hit=751596 read=253687 dirtied=3449 written=423 -> Nested Loop (cost=503475.46..2184723.48 rows=24725 width=38) (actual time=20369.943..29521.330 rows=24130 loops=1) Buffers: shared hit=751596 read=253687 dirtied=3449 written=423 -> Nested Loop (cost=503475.46..2177671.91 rows=24725 width=16) (actual time=20369.858..29325.471 rows=24130 loops=1) Buffers: shared hit=703336 read=253687 dirtied=3449 written=423 -> Hash Join (cost=503475.46..2170471.95 rows=24725 width=16) (actual time=20369.814..28925.058 rows=24130 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=630816 read=253687 dirtied=3449 written=423 -> Nested Loop (cost=0.00..1664717.70 rows=406308 width=16) (actual time=0.524..7325.032 rows=397849 loops=1) Buffers: shared hit=229287 read=239313 dirtied=3449 written=423 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..46462.06 rows=13373 width=4) (actual time=0.441..232.005 rows=13245 loops=1) Index Cond: (p_type = 'LARGE ANODIZED NICKEL'::text) Heap Fetches: 13245 Buffers: shared hit=2813 read=8582 written=17 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..120.70 rows=31 width=20) (actual time=0.052..0.520 rows=30 loops=13245) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=226474 read=230731 dirtied=3449 written=406 -> Hash (cost=491917.33..491917.33 rows=924650 width=8) (actual time=20368.330..20368.330 rows=912000 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35625kB Buffers: shared hit=401526 read=14374 -> Hash Join (cost=139424.92..491917.33 rows=924650 width=8) (actual time=4375.200..19382.493 rows=912000 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=401526 read=14374 -> Bitmap Heap Scan on orders (cost=100394.29..426303.03 rows=4623249 width=12) (actual time=3152.670..7098.050 rows=4561702 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=256215 read=13536 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..99238.48 rows=4623249 width=0) (actual time=3004.962..3004.962 rows=4616605 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared read=13191 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=1222.036..1222.036 rows=299493 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10530kB Buffers: shared hit=145311 read=838 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=34.122..1052.670 rows=299493 loops=1) Buffers: shared hit=145311 read=838 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.044..0.101 rows=5 loops=1) Hash Cond: (n1.n_regionkey = region.r_regionkey) Buffers: shared hit=2 -> Seq Scan on nation n1 (cost=0.00..1.25 rows=25 width=8) (actual time=0.008..0.021 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.021..0.021 rows=1 loops=1) Buckets: 1024 Batches: 1 Memory Usage: 1kB Buffers: shared hit=1 -> Seq Scan on region (cost=0.00..1.06 rows=1 width=4) (actual time=0.015..0.018 rows=1 loops=1) Filter: (r_name = 'AFRICA'::bpchar) Rows Removed by Filter: 4 Buffers: shared hit=1 -> Bitmap Heap Scan on customer (cost=905.09..6455.63 rows=60000 width=8) (actual time=30.159..192.304 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=145309 read=838 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=20.386..20.386 rows=59899 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=8 read=825 -> Index Scan using pk_supplier on supplier (cost=0.00..0.28 rows=1 width=8) (actual time=0.014..0.014 rows=1 loops=24130) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72520 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.005..0.005 rows=1 loops=24130) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48260 Total runtime: 29608.743 ms (64 rows) COMMIT; COMMIT