BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'IRAN' 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 = 'MEDIUM PLATED COPPER' ) as all_nations group by o_year order by o_year; QUERY PLAN ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1749862.28..1749864.10 rows=729 width=38) (actual time=10757.836..10757.836 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=1783051 read=223048 dirtied=48 written=248 -> HashAggregate (cost=1749814.85..1749827.61 rows=729 width=38) (actual time=10757.754..10757.756 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=1783048 read=223048 dirtied=48 written=248 -> Hash Join (cost=39454.74..1749318.09 rows=24838 width=38) (actual time=1010.132..10715.357 rows=24298 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=1783048 read=223048 dirtied=48 written=248 -> Nested Loop (cost=39453.18..1748850.82 rows=24838 width=16) (actual time=1010.066..10679.748 rows=24298 loops=1) Buffers: shared hit=1783044 read=223048 dirtied=48 written=248 -> Hash Join (cost=39452.89..1740836.55 rows=24838 width=16) (actual time=1010.038..10466.315 rows=24298 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1710008 read=223048 dirtied=48 written=248 -> Nested Loop (cost=422.20..1701091.78 rows=124188 width=20) (actual time=9.351..9376.706 rows=121113 loops=1) Buffers: shared hit=1575698 read=211203 dirtied=48 written=247 -> Nested Loop (cost=421.77..1500246.27 rows=410168 width=16) (actual time=8.853..4654.545 rows=398723 loops=1) Buffers: shared hit=282383 read=185865 dirtied=45 written=219 -> Bitmap Heap Scan on part (cost=417.05..28323.50 rows=13500 width=4) (actual time=8.733..192.962 rows=13291 loops=1) Recheck Cond: ((p_type)::text = 'MEDIUM PLATED COPPER'::text) Heap Blocks: exact=11355 Buffers: shared hit=383 read=11055 written=14 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..413.68 rows=13500 width=0) (actual time=6.176..6.176 rows=13291 loops=1) Index Cond: ((p_type)::text = 'MEDIUM PLATED COPPER'::text) Buffers: shared read=83 -> Bitmap Heap Scan on lineitem (cost=4.72..108.72 rows=31 width=20) (actual time=0.043..0.324 rows=30 loops=13291) Recheck Cond: (l_partkey = part.p_partkey) Heap Blocks: exact=401564 Buffers: shared hit=282000 read=174810 dirtied=45 written=205 -> Bitmap Index Scan on lineitem_l_partkey_l_quantity_l_shipmode_idx (cost=0.00..4.71 rows=31 width=0) (actual time=0.027..0.027 rows=30 loops=13291) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=39613 read=15633 written=17 -> Index Scan using orders_o_orderkey_o_orderdate_idx on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.011..0.011 rows=0 loops=398723) Index Cond: ((o_orderkey = lineitem.l_orderkey) AND (o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=1293315 read=25338 dirtied=3 written=28 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=997.031..997.031 rows=299838 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14638kB Buffers: shared hit=134310 read=11845 written=1 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=26.611..890.529 rows=299838 loops=1) Buffers: shared hit=134310 read=11845 written=1 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.064..0.098 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..0.018 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.027..0.027 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=21.134..166.829 rows=59968 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145317 Buffers: shared hit=134308 read=11845 written=1 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=14.045..14.045 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=0.007..0.008 rows=1 loops=24298) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=73036 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.024..0.024 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=0.005..0.007 rows=25 loops=1) Buffers: shared hit=1 Planning time: 10.625 ms Execution time: 10758.895 ms (70 rows) COMMIT; COMMIT