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 = 'PROMO BRUSHED BRASS' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2128325.97..2128327.80 rows=732 width=38) (actual time=63550.128..63550.128 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=785778 read=220660 dirtied=3372 written=16 -> HashAggregate (cost=2128278.33..2128291.14 rows=732 width=38) (actual time=63550.036..63550.039 rows=2 loops=1) Buffers: shared hit=785775 read=220660 dirtied=3372 written=16 -> Nested Loop (cost=503668.41..2127803.51 rows=23741 width=38) (actual time=36630.665..63425.204 rows=24088 loops=1) Buffers: shared hit=785775 read=220660 dirtied=3372 written=16 -> Nested Loop (cost=503668.41..2121032.58 rows=23741 width=16) (actual time=36630.598..61745.045 rows=24088 loops=1) Buffers: shared hit=737599 read=220660 dirtied=3372 written=16 -> Hash Join (cost=503668.41..2114118.00 rows=23745 width=16) (actual time=36630.566..59967.777 rows=24088 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=665199 read=220660 dirtied=3372 written=16 -> Nested Loop (cost=0.00..1608258.62 rows=390705 width=16) (actual time=0.511..21942.173 rows=398625 loops=1) Buffers: shared hit=264827 read=205076 dirtied=3119 written=5 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..44880.68 rows=12847 width=4) (actual time=0.399..728.058 rows=13257 loops=1) Index Cond: (p_type = 'PROMO BRUSHED BRASS'::text) Heap Fetches: 13257 Buffers: shared hit=3604 read=7799 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..121.38 rows=31 width=20) (actual time=0.175..1.580 rows=30 loops=13257) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=261223 read=197277 dirtied=3119 written=5 -> Hash (cost=492113.57..492113.57 rows=924387 width=8) (actual time=36627.135..36627.135 rows=911176 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35593kB Buffers: shared hit=400369 read=15584 dirtied=253 written=11 -> Hash Join (cost=139395.44..492113.57 rows=924387 width=8) (actual time=8559.305..35955.115 rows=911176 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=400369 read=15584 dirtied=253 written=11 -> Bitmap Heap Scan on orders (cost=100364.82..426506.83 rows=4621934 width=12) (actual time=4633.718..17319.095 rows=4561665 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=256703 read=13312 dirtied=253 written=5 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..99209.33 rows=4621934 width=0) (actual time=4485.740..4485.740 rows=4621215 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=707 read=12495 written=5 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=3925.282..3925.282 rows=299436 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10528kB Buffers: shared hit=143666 read=2272 written=6 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=56.917..3721.272 rows=299436 loops=1) Buffers: shared hit=143666 read=2272 written=6 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.874..0.932 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=0.826..0.838 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.026..0.026 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=0.023..0.024 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=46.672..724.072 rows=59887 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=143664 read=2272 written=6 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=35.855..35.855 rows=59887 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=175 read=659 written=2 -> Index Scan using pk_supplier on supplier (cost=0.00..0.28 rows=1 width=8) (actual time=0.070..0.070 rows=1 loops=24088) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72400 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.064..0.065 rows=1 loops=24088) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48176 Total runtime: 63566.937 ms (64 rows) COMMIT; COMMIT