BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'KENYA' 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 = 'STANDARD ANODIZED BRASS' ) as all_nations group by o_year order by o_year; QUERY PLAN ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1746749.04..1746750.87 rows=730 width=38) (actual time=9540.919..9540.920 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=2031181 read=235311 dirtied=42 written=20 -> HashAggregate (cost=1746701.55..1746714.32 rows=730 width=38) (actual time=9540.854..9540.855 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=2031178 read=235311 dirtied=42 written=20 -> Hash Join (cost=39454.64..1746208.85 rows=24635 width=38) (actual time=980.998..9501.182 rows=24124 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=2031178 read=235311 dirtied=42 written=20 -> Nested Loop (cost=39453.08..1745745.38 rows=24635 width=16) (actual time=980.938..9467.679 rows=24124 loops=1) Buffers: shared hit=2031174 read=235311 dirtied=42 written=20 -> Hash Join (cost=39452.79..1737788.52 rows=24660 width=16) (actual time=980.914..9289.350 rows=24124 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1958690 read=235311 dirtied=42 written=20 -> Nested Loop (cost=422.10..1698048.85 rows=123301 width=20) (actual time=7.173..8241.686 rows=120102 loops=1) Buffers: shared hit=1848642 read=199211 dirtied=42 written=20 -> Nested Loop (cost=421.67..1498793.55 rows=406936 width=16) (actual time=6.869..3768.794 rows=395544 loops=1) Buffers: shared hit=269610 read=193906 dirtied=41 written=18 -> Bitmap Heap Scan on part (cost=416.95..28307.28 rows=13487 width=4) (actual time=6.778..125.341 rows=13198 loops=1) Recheck Cond: ((p_type)::text = 'STANDARD ANODIZED BRASS'::text) Heap Blocks: exact=11321 Buffers: shared hit=3980 read=7423 written=3 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..413.58 rows=13487 width=0) (actual time=4.566..4.566 rows=13198 loops=1) Index Cond: ((p_type)::text = 'STANDARD ANODIZED BRASS'::text) Buffers: shared read=82 -> Bitmap Heap Scan on lineitem (cost=4.72..108.72 rows=31 width=20) (actual time=0.034..0.265 rows=30 loops=13198) Recheck Cond: (l_partkey = part.p_partkey) Heap Blocks: exact=397299 Buffers: shared hit=265630 read=186483 dirtied=41 written=15 -> Bitmap Index Scan on lineitem_l_partkey_l_quantity_l_shipmode_idx (cost=0.00..4.71 rows=31 width=0) (actual time=0.023..0.023 rows=30 loops=13198) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=38956 read=15858 written=1 -> Index Scan using pk_orders on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.011..0.011 rows=0 loops=395544) 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=1579032 read=5305 dirtied=1 written=2 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=970.025..970.025 rows=299493 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14626kB Buffers: shared hit=110048 read=36100 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=19.668..879.650 rows=299493 loops=1) Buffers: shared hit=110048 read=36100 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.051..0.077 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..0.013 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.025..0.025 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=0.019..0.020 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=17.243..165.247 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145314 Buffers: shared hit=110046 read=36100 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=11.197..11.197 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..0.006 rows=1 loops=24124) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72484 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.021..0.021 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..0.008 rows=25 loops=1) Buffers: shared hit=1 Planning time: 7.493 ms Execution time: 9541.916 ms (72 rows) COMMIT; COMMIT