BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'CANADA' 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 = 'AMERICA' and s_nationkey = n2.n_nationkey and o_orderdate between date '1995-01-01' and date '1996-12-31' and p_type = 'MEDIUM ANODIZED COPPER' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2179163.26..2179165.09 rows=731 width=38) (actual time=29265.933..29265.933 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=742224 read=258882 dirtied=2759 written=24001 -> HashAggregate (cost=2179115.69..2179128.49 rows=731 width=38) (actual time=29265.844..29265.846 rows=2 loops=1) Buffers: shared hit=742221 read=258882 dirtied=2759 written=24001 -> Nested Loop (cost=502629.87..2178624.29 rows=24570 width=38) (actual time=20412.904..29198.068 rows=23922 loops=1) Buffers: shared hit=742221 read=258882 dirtied=2759 written=24001 -> Nested Loop (cost=502629.87..2171616.93 rows=24570 width=16) (actual time=20412.833..29017.939 rows=23922 loops=1) Buffers: shared hit=694377 read=258882 dirtied=2759 written=24001 -> Hash Join (cost=502629.87..2164462.10 rows=24570 width=16) (actual time=20412.784..28670.681 rows=23922 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=622487 read=258882 dirtied=2759 written=24001 -> Nested Loop (cost=0.00..1659564.00 rows=404507 width=16) (actual time=0.462..7108.915 rows=395216 loops=1) Buffers: shared hit=223056 read=242886 dirtied=2759 written=24001 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..46321.22 rows=13327 width=4) (actual time=0.368..277.542 rows=13196 loops=1) Index Cond: (p_type = 'MEDIUM ANODIZED COPPER'::text) Heap Fetches: 13196 Buffers: shared hit=1 read=11438 written=1205 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..120.74 rows=31 width=20) (actual time=0.047..0.502 rows=30 loops=13196) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=223055 read=231448 dirtied=2759 written=22796 -> Hash (cost=491104.33..491104.33 rows=922043 width=8) (actual time=20411.079..20411.079 rows=911207 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35595kB Buffers: shared hit=399428 read=15996 -> Hash Join (cost=139135.34..491104.33 rows=922043 width=8) (actual time=4676.380..19937.201 rows=911207 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=399428 read=15996 -> Bitmap Heap Scan on orders (cost=100104.71..425564.97 rows=4610217 width=12) (actual time=3276.559..7462.984 rows=4561761 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=254318 read=15168 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..98952.16 rows=4610217 width=0) (actual time=3126.457..3126.457 rows=4612043 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared read=13179 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=1399.567..1399.567 rows=299436 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10528kB Buffers: shared hit=145110 read=828 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=33.211..1235.753 rows=299436 loops=1) Buffers: shared hit=145110 read=828 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.046..0.103 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=0.016..0.029 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.018..0.018 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=0.015..0.017 rows=1 loops=1) Filter: (r_name = 'AMERICA'::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=31.104..228.213 rows=59887 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=145108 read=828 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=21.244..21.244 rows=59887 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=7 read=827 -> Index Scan using pk_supplier on supplier (cost=0.00..0.28 rows=1 width=8) (actual time=0.012..0.012 rows=1 loops=23922) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=71890 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.004..0.005 rows=1 loops=23922) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=47844 Total runtime: 29277.840 ms (64 rows) COMMIT; COMMIT