BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'CHINA' 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 = 'ASIA' and s_nationkey = n2.n_nationkey and o_orderdate between date '1995-01-01' and date '1996-12-31' and p_type = 'ECONOMY BURNISHED STEEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2147025.88..2147027.71 rows=733 width=38) (actual time=26088.753..26088.753 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=669504 read=336712 dirtied=3457 -> HashAggregate (cost=2146978.17..2146990.99 rows=733 width=38) (actual time=26088.688..26088.688 rows=2 loops=1) Buffers: shared hit=669501 read=336712 dirtied=3457 -> Nested Loop (cost=502680.45..2146497.45 rows=24036 width=38) (actual time=20289.278..26043.137 rows=24289 loops=1) Buffers: shared hit=669501 read=336712 dirtied=3457 -> Nested Loop (cost=502680.45..2139642.38 rows=24036 width=16) (actual time=20289.217..25943.123 rows=24289 loops=1) Buffers: shared hit=620923 read=336712 dirtied=3457 -> Hash Join (cost=502680.45..2132635.19 rows=24063 width=16) (actual time=20289.186..25710.757 rows=24289 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=547911 read=336712 dirtied=3457 -> Nested Loop (cost=0.00..1627738.13 rows=395195 width=16) (actual time=12.991..4358.575 rows=398416 loops=1) Buffers: shared hit=246861 read=222302 dirtied=3457 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..45443.87 rows=13033 width=4) (actual time=12.892..181.532 rows=13296 loops=1) Index Cond: (p_type = 'ECONOMY BURNISHED STEEL'::text) Heap Fetches: 13296 Buffers: shared hit=2 read=11459 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..121.10 rows=31 width=20) (actual time=0.029..0.304 rows=30 loops=13296) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=246859 read=210843 dirtied=3457 -> Hash (cost=491138.23..491138.23 rows=923378 width=8) (actual time=20275.272..20275.272 rows=912317 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35638kB Buffers: shared hit=301047 read=114410 -> Hash Join (cost=139283.74..491138.23 rows=923378 width=8) (actual time=4496.102..19525.449 rows=912317 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=301047 read=114410 -> Bitmap Heap Scan on orders (cost=100253.12..425560.49 rows=4616891 width=12) (actual time=3083.083..7021.932 rows=4557203 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=190915 read=78304 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..99098.90 rows=4616891 width=0) (actual time=2973.187..2973.187 rows=4607485 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared read=13165 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=1412.776..1412.776 rows=300270 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10557kB Buffers: shared hit=110132 read=36106 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=23.296..1300.186 rows=300270 loops=1) Buffers: shared hit=110132 read=36106 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.034..0.080 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..0.016 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.017..0.017 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..0.015 rows=1 loops=1) Filter: (r_name = 'ASIA'::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=22.608..246.732 rows=60054 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=110130 read=36106 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=15.090..15.090 rows=60054 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=5 read=831 -> Index Scan using pk_supplier on supplier (cost=0.00..0.28 rows=1 width=8) (actual time=0.008..0.008 rows=1 loops=24289) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=73012 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.002..0.002 rows=1 loops=24289) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48578 Total runtime: 26101.235 ms (64 rows) COMMIT; COMMIT