BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'UNITED KINGDOM' 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 = 'EUROPE' and s_nationkey = n2.n_nationkey and o_orderdate between date '1995-01-01' and date '1996-12-31' and p_type = 'MEDIUM BURNISHED NICKEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2121905.47..2121907.30 rows=733 width=38) (actual time=15743.522..15743.522 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=816434 read=185613 -> HashAggregate (cost=2121857.76..2121870.59 rows=733 width=38) (actual time=15743.468..15743.469 rows=2 loops=1) Buffers: shared hit=816431 read=185613 -> Nested Loop (cost=495782.92..2121387.12 rows=23532 width=38) (actual time=11471.509..15712.484 rows=24371 loops=1) Buffers: shared hit=816431 read=185613 -> Nested Loop (cost=495782.92..2114675.79 rows=23532 width=16) (actual time=11471.455..15652.484 rows=24371 loops=1) Buffers: shared hit=767689 read=185613 -> Hash Join (cost=495782.92..2107815.62 rows=23558 width=16) (actual time=11471.410..15492.502 rows=24371 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=696898 read=183165 -> Nested Loop (cost=0.00..1609862.59 rows=386906 width=16) (actual time=1.049..3080.869 rows=400868 loops=1) Buffers: shared hit=311835 read=156070 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..45001.32 rows=12887 width=4) (actual time=0.777..126.246 rows=13361 loops=1) Index Cond: (p_type = 'MEDIUM BURNISHED NICKEL'::text) Heap Fetches: 13361 Buffers: shared hit=2 read=11512 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..121.12 rows=31 width=20) (actual time=0.022..0.213 rows=30 loops=13361) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=311833 read=144558 -> Hash (cost=484354.83..484354.83 rows=914247 width=8) (actual time=11469.225..11469.225 rows=913948 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35702kB Buffers: shared hit=385060 read=27095 -> Hash Join (cost=135979.69..484354.83 rows=914247 width=8) (actual time=1911.125..11190.203 rows=913948 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=385060 read=27095 -> Bitmap Heap Scan on orders (cost=96949.06..419039.60 rows=4571236 width=12) (actual time=1290.222..3284.337 rows=4561961 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=239716 read=26262 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..95806.26 rows=4571236 width=0) (actual time=1203.094..1203.094 rows=4561961 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared read=12456 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=620.612..620.612 rows=300963 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10581kB Buffers: shared hit=145344 read=833 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=32.846..552.281 rows=300963 loops=1) Buffers: shared hit=145344 read=833 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.029..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=0.005..0.021 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.012..0.012 rows=1 loops=1) Buckets: 1024 Batches: 1 Memory Usage: 1kB Buffers: shared hit=1 -> Seq Scan on region (cost=0.00..1.06 rows=1 width=4) (actual time=0.008..0.009 rows=1 loops=1) Filter: (r_name = 'EUROPE'::bpchar) Rows Removed by Filter: 4 Buffers: shared hit=1 -> Bitmap Heap Scan on customer (cost=905.09..6455.63 rows=60000 width=8) (actual time=19.898..100.066 rows=60193 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=145342 read=833 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=13.904..13.904 rows=60193 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=6 read=833 -> Index Scan using pk_supplier on supplier (cost=0.00..0.28 rows=1 width=8) (actual time=0.006..0.006 rows=1 loops=24371) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=70791 read=2448 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.001..0.001 rows=1 loops=24371) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48742 Total runtime: 15748.688 ms (64 rows) COMMIT; COMMIT