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 = 'MEDIUM ANODIZED BRASS' ) as all_nations group by o_year order by o_year; QUERY PLAN ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1723331.21..1723333.03 rows=727 width=38) (actual time=10901.612..10901.613 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=1758288 read=253487 dirtied=1992 written=649 -> HashAggregate (cost=1723283.94..1723296.66 rows=727 width=38) (actual time=10901.550..10901.552 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=1758285 read=253487 dirtied=1992 written=649 -> Hash Join (cost=39444.58..1722799.22 rows=24236 width=38) (actual time=1063.919..10858.941 rows=24218 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=1758285 read=253487 dirtied=1992 written=649 -> Nested Loop (cost=39443.02..1722343.23 rows=24236 width=16) (actual time=1063.858..10817.910 rows=24218 loops=1) Buffers: shared hit=1758281 read=253487 dirtied=1992 written=649 -> Hash Join (cost=39442.72..1714523.19 rows=24236 width=16) (actual time=1063.840..10599.281 rows=24218 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1685494 read=253487 dirtied=1992 written=649 -> Nested Loop (cost=412.04..1674795.72 rows=121181 width=20) (actual time=7.347..9403.200 rows=121566 loops=1) Buffers: shared hit=1575339 read=217494 dirtied=1992 written=601 -> Nested Loop (cost=411.60..1478407.78 rows=401071 width=16) (actual time=7.250..4390.486 rows=400203 loops=1) Buffers: shared hit=290793 read=178458 dirtied=1953 written=477 -> Bitmap Heap Scan on part (cost=411.04..28006.04 rows=13240 width=4) (actual time=7.185..172.484 rows=13288 loops=1) Recheck Cond: ((p_type)::text = 'MEDIUM ANODIZED BRASS'::text) Heap Blocks: exact=11356 Buffers: shared hit=2570 read=8869 written=25 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..407.73 rows=13240 width=0) (actual time=4.901..4.901 rows=13288 loops=1) Index Cond: ((p_type)::text = 'MEDIUM ANODIZED BRASS'::text) Buffers: shared read=83 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.56..109.24 rows=31 width=20) (actual time=0.029..0.306 rows=30 loops=13288) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=288223 read=169589 dirtied=1953 written=452 -> Index Scan using orders_o_orderkey_o_orderdate_idx on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.012..0.012 rows=0 loops=400203) Index Cond: ((o_orderkey = lineitem.l_orderkey) AND (o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=1284546 read=39036 dirtied=39 written=124 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=1051.603..1051.603 rows=299493 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14626kB Buffers: shared hit=110155 read=35993 written=48 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=21.170..953.028 rows=299493 loops=1) Buffers: shared hit=110155 read=35993 written=48 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.049..0.076 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=0.004..0.009 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=0.013..0.015 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=19.165..179.115 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145314 Buffers: shared hit=110153 read=35993 written=48 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=12.399..12.399 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=24218) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72787 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.020..0.020 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..0.009 rows=25 loops=1) Buffers: shared hit=1 Planning time: 7.719 ms Execution time: 10903.053 ms (66 rows) COMMIT; COMMIT