BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'MOZAMBIQUE' 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 = 'PROMO POLISHED STEEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1731648.77..1731650.59 rows=727 width=38) (actual time=10923.876..10923.877 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=1815965 read=201159 dirtied=24 -> HashAggregate (cost=1731601.50..1731614.22 rows=727 width=38) (actual time=10923.812..10923.813 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=1815962 read=201159 dirtied=24 -> Hash Join (cost=39449.71..1731114.06 rows=24372 width=38) (actual time=878.138..10883.826 rows=24465 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=1815962 read=201159 dirtied=24 -> Nested Loop (cost=39448.15..1730655.52 rows=24372 width=16) (actual time=878.075..10846.412 rows=24465 loops=1) Buffers: shared hit=1815958 read=201159 dirtied=24 -> Hash Join (cost=39447.86..1722791.58 rows=24372 width=16) (actual time=878.051..10629.573 rows=24465 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1742406 read=201159 dirtied=24 -> Nested Loop (cost=417.17..1683060.20 rows=121860 width=20) (actual time=7.872..9621.092 rows=121541 loops=1) Buffers: shared hit=1599806 read=197611 dirtied=24 -> Nested Loop (cost=416.74..1485576.02 rows=403319 width=16) (actual time=7.578..4735.999 rows=401422 loops=1) Buffers: shared hit=287008 read=183214 dirtied=18 -> Bitmap Heap Scan on part (cost=412.02..28159.98 rows=13367 width=4) (actual time=7.463..194.327 rows=13376 loops=1) Recheck Cond: ((p_type)::text = 'PROMO POLISHED STEEL'::text) Heap Blocks: exact=11470 Buffers: shared hit=1 read=11553 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..408.68 rows=13367 width=0) (actual time=5.106..5.106 rows=13376 loops=1) Index Cond: ((p_type)::text = 'PROMO POLISHED STEEL'::text) Buffers: shared read=84 -> Bitmap Heap Scan on lineitem (cost=4.72..108.72 rows=31 width=20) (actual time=0.041..0.328 rows=30 loops=13376) Recheck Cond: (l_partkey = part.p_partkey) Heap Blocks: exact=403042 Buffers: shared hit=287007 read=171661 dirtied=18 -> 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=13376) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=39660 read=15966 -> Index Scan using orders_o_orderkey_o_orderdate_idx on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.011..0.012 rows=0 loops=401422) Index Cond: ((o_orderkey = lineitem.l_orderkey) AND (o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=1312798 read=14397 dirtied=6 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=866.891..866.891 rows=299493 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14626kB Buffers: shared hit=142600 read=3548 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=21.786..773.067 rows=299493 loops=1) Buffers: shared hit=142600 read=3548 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.054..0.085 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..0.014 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.029..0.029 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=0.022..0.024 rows=1 loops=1) Filter: (r_name = 'AFRICA'::bpchar) Rows Removed by Filter: 4 Buffers: shared hit=1 -> Bitmap Heap Scan on customer (cost=905.11..6455.64 rows=60000 width=8) (actual time=19.658..143.765 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145314 Buffers: shared hit=142598 read=3548 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=12.771..12.771 rows=59899 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=7 read=825 -> 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=24465) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=73552 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.025..0.025 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=0.004..0.007 rows=25 loops=1) Buffers: shared hit=1 Planning time: 8.142 ms Execution time: 10925.340 ms (70 rows) COMMIT; COMMIT