BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'KENYA' 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 = 'MEDIUM POLISHED STEEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2157760.19..2157762.02 rows=732 width=38) (actual time=58725.539..58725.539 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=755495 read=247817 dirtied=2231 written=1370 -> HashAggregate (cost=2157712.55..2157725.36 rows=732 width=38) (actual time=58725.449..58725.452 rows=2 loops=1) Buffers: shared hit=755492 read=247817 dirtied=2231 written=1370 -> Nested Loop (cost=501830.26..2157228.43 rows=24206 width=38) (actual time=32532.792..58603.478 rows=24017 loops=1) Buffers: shared hit=755492 read=247817 dirtied=2231 written=1370 -> Nested Loop (cost=501830.26..2150324.88 rows=24206 width=16) (actual time=32532.708..57172.020 rows=24017 loops=1) Buffers: shared hit=707458 read=247817 dirtied=2231 written=1370 -> Hash Join (cost=501830.26..2143274.88 rows=24210 width=16) (actual time=32532.666..55620.207 rows=24017 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=635264 read=247817 dirtied=2231 written=1370 -> Nested Loop (cost=0.00..1639210.79 rows=398348 width=16) (actual time=0.497..21770.018 rows=397051 loops=1) Buffers: shared hit=235536 read=232438 dirtied=2231 written=68 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..45761.79 rows=13140 width=4) (actual time=0.385..647.309 rows=13278 loops=1) Index Cond: (p_type = 'MEDIUM POLISHED STEEL'::text) Heap Fetches: 13278 Buffers: shared hit=3985 read=7466 written=2 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..120.96 rows=31 width=20) (actual time=0.166..1.571 rows=30 loops=13278) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=231551 read=224972 dirtied=2231 written=66 -> Hash (cost=490320.96..490320.96 rows=920744 width=8) (actual time=32529.594..32529.594 rows=911003 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35587kB Buffers: shared hit=399725 read=15379 written=1302 -> Hash Join (cost=138992.75..490320.96 rows=920744 width=8) (actual time=7287.738..31877.832 rows=911003 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=399725 read=15379 written=1302 -> Bitmap Heap Scan on orders (cost=99962.13..424818.94 rows=4603721 width=12) (actual time=4525.910..15047.728 rows=4557089 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=254415 read=14540 written=1209 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..98811.20 rows=4603721 width=0) (actual time=4391.274..4391.274 rows=4604552 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=352 read=12802 written=1087 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=2761.485..2761.485 rows=299493 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10530kB Buffers: shared hit=145310 read=839 written=93 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=42.211..2564.191 rows=299493 loops=1) Buffers: shared hit=145310 read=839 written=93 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.040..0.112 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=0.005..0.020 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.019..0.019 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=0.014..0.016 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=42.422..492.724 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=145308 read=839 written=93 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=32.574..32.574 rows=59899 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=8 read=825 written=92 -> Index Scan using pk_supplier on supplier (cost=0.00..0.28 rows=1 width=8) (actual time=0.061..0.061 rows=1 loops=24017) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72194 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.054..0.055 rows=1 loops=24017) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48034 Total runtime: 58737.696 ms (64 rows) COMMIT; COMMIT