BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'ETHIOPIA' 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 BRUSHED NICKEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1742721.03..1742722.86 rows=729 width=38) (actual time=10680.733..10680.734 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=2047385 read=257682 dirtied=311 written=30 -> HashAggregate (cost=1742673.61..1742686.37 rows=729 width=38) (actual time=10680.672..10680.673 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=2047382 read=257682 dirtied=311 written=30 -> Hash Join (cost=39454.44..1742183.41 rows=24510 width=38) (actual time=775.110..10640.635 rows=24405 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=2047382 read=257682 dirtied=311 written=30 -> Nested Loop (cost=39452.87..1741722.29 rows=24510 width=16) (actual time=775.053..10607.191 rows=24405 loops=1) Buffers: shared hit=2047378 read=257682 dirtied=311 written=30 -> Hash Join (cost=39452.58..1733813.81 rows=24510 width=16) (actual time=775.028..10423.284 rows=24405 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1974036 read=257682 dirtied=311 written=30 -> Nested Loop (cost=421.89..1694078.47 rows=122549 width=20) (actual time=7.816..9578.021 rows=122578 loops=1) Buffers: shared hit=1828713 read=256857 dirtied=311 written=30 -> Nested Loop (cost=421.46..1495815.14 rows=404917 width=16) (actual time=7.561..3925.515 rows=403056 loops=1) Buffers: shared hit=298154 read=173011 dirtied=19 written=22 -> Bitmap Heap Scan on part (cost=416.74..28274.78 rows=13460 width=4) (actual time=7.454..171.229 rows=13430 loops=1) Recheck Cond: ((p_type)::text = 'PROMO BRUSHED NICKEL'::text) Heap Blocks: exact=11462 Buffers: shared hit=144 read=11402 written=1 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..413.38 rows=13460 width=0) (actual time=5.199..5.199 rows=13430 loops=1) Index Cond: ((p_type)::text = 'PROMO BRUSHED NICKEL'::text) Buffers: shared read=84 -> Bitmap Heap Scan on lineitem (cost=4.72..108.72 rows=31 width=20) (actual time=0.037..0.269 rows=30 loops=13430) Recheck Cond: (l_partkey = part.p_partkey) Heap Blocks: exact=403810 Buffers: shared hit=298010 read=161609 dirtied=19 written=21 -> Bitmap Index Scan on lineitem_l_partkey_l_quantity_l_shipmode_idx (cost=0.00..4.71 rows=31 width=0) (actual time=0.024..0.024 rows=30 loops=13430) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=40209 read=15600 -> Index Scan using pk_orders on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.013..0.013 rows=0 loops=403056) Index Cond: (o_orderkey = lineitem.l_orderkey) Filter: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Rows Removed by Filter: 1 Buffers: shared hit=1530559 read=83846 dirtied=292 written=8 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=763.823..763.823 rows=299493 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14626kB Buffers: shared hit=145323 read=825 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=20.526..677.620 rows=299493 loops=1) Buffers: shared hit=145323 read=825 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.041..0.075 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=0.007..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: 9kB Buffers: shared hit=1 -> Seq Scan on region (cost=0.00..1.06 rows=1 width=4) (actual time=0.009..0.010 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=17.980..125.278 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145314 Buffers: shared hit=145321 read=825 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=11.748..11.748 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=0.006..0.007 rows=1 loops=24405) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=73342 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.019..0.019 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..0.007 rows=25 loops=1) Buffers: shared hit=1 Planning time: 7.727 ms Execution time: 10681.902 ms (72 rows) COMMIT; COMMIT