BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'IRAQ' 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 = 'MIDDLE EAST' and s_nationkey = n2.n_nationkey and o_orderdate between date '1995-01-01' and date '1996-12-31' and p_type = 'SMALL PLATED TIN' ) as all_nations group by o_year order by o_year; QUERY PLAN ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1702161.85..1702163.67 rows=729 width=38) (actual time=8464.527..8464.527 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=1806638 read=207364 dirtied=1489 written=440 -> HashAggregate (cost=1702114.42..1702127.18 rows=729 width=38) (actual time=8464.472..8464.472 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=1806635 read=207364 dirtied=1489 written=440 -> Hash Join (cost=39439.08..1701635.76 rows=23933 width=38) (actual time=966.261..8425.382 rows=24285 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=1806635 read=207364 dirtied=1489 written=440 -> Nested Loop (cost=39437.52..1701185.46 rows=23933 width=16) (actual time=966.202..8391.408 rows=24285 loops=1) Buffers: shared hit=1806631 read=207364 dirtied=1489 written=440 -> Hash Join (cost=39437.23..1693463.19 rows=23933 width=16) (actual time=966.187..8227.673 rows=24285 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1733632 read=207364 dirtied=1489 written=440 -> Nested Loop (cost=406.54..1653744.43 rows=119663 width=20) (actual time=7.089..7183.751 rows=121776 loops=1) Buffers: shared hit=1611594 read=183247 dirtied=1489 written=420 -> Nested Loop (cost=406.11..1460220.01 rows=395223 width=16) (actual time=6.980..3558.957 rows=400574 loops=1) Buffers: shared hit=302155 read=167778 dirtied=1479 written=383 -> Bitmap Heap Scan on part (cost=405.54..27766.09 rows=13047 width=4) (actual time=6.916..176.102 rows=13365 loops=1) Recheck Cond: ((p_type)::text = 'SMALL PLATED TIN'::text) Heap Blocks: exact=11430 Buffers: shared read=11499 written=34 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..402.28 rows=13047 width=0) (actual time=4.581..4.581 rows=13365 loops=1) Index Cond: ((p_type)::text = 'SMALL PLATED TIN'::text) Buffers: shared read=69 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.56..109.48 rows=31 width=20) (actual time=0.025..0.243 rows=30 loops=13365) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=302155 read=156279 dirtied=1479 written=349 -> Index Scan using orders_o_orderkey_o_orderdate_idx on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.008..0.008 rows=0 loops=400574) Index Cond: ((o_orderkey = lineitem.l_orderkey) AND (o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=1309439 read=15469 dirtied=10 written=37 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=955.920..955.920 rows=299838 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14638kB Buffers: shared hit=122038 read=24117 written=20 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=21.639..850.148 rows=299838 loops=1) Buffers: shared hit=122038 read=24117 written=20 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.046..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=0.006..0.012 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.022..0.022 rows=1 loops=1) Buckets: 1024 Batches: 1 Memory Usage: 9kB Buffers: shared hit=1 -> Seq Scan on region (cost=0.00..1.06 rows=1 width=4) (actual time=0.015..0.016 rows=1 loops=1) Filter: (r_name = 'MIDDLE EAST'::bpchar) Rows Removed by Filter: 4 Buffers: shared hit=1 -> Bitmap Heap Scan on customer (cost=905.11..6455.64 rows=60000 width=8) (actual time=19.453..158.955 rows=59968 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145317 Buffers: shared hit=122036 read=24117 written=20 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=12.478..12.478 rows=59968 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=5 read=831 -> Index Scan using pk_supplier on supplier (cost=0.29..0.31 rows=1 width=8) (actual time=0.005..0.006 rows=1 loops=24285) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72999 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.022..0.022 rows=25 loops=1) Buckets: 1024 Batches: 1 Memory Usage: 10kB Buffers: shared hit=1 -> Seq Scan on nation n2 (cost=0.00..1.25 rows=25 width=30) (actual time=0.003..0.005 rows=25 loops=1) Buffers: shared hit=1 Planning time: 7.998 ms Execution time: 8465.231 ms (66 rows) COMMIT; COMMIT