BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'MOROCCO' 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 COPPER' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2198943.24..2198945.07 rows=730 width=38) (actual time=27012.194..27012.195 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=740626 read=260751 dirtied=2809 written=3953 -> HashAggregate (cost=2198895.75..2198908.53 rows=730 width=38) (actual time=27012.116..27012.116 rows=2 loops=1) Buffers: shared hit=740623 read=260751 dirtied=2809 written=3953 -> Nested Loop (cost=501788.40..2198399.19 rows=24828 width=38) (actual time=20130.977..26957.177 rows=24106 loops=1) Buffers: shared hit=740623 read=260751 dirtied=2809 written=3953 -> Nested Loop (cost=501788.40..2191318.25 rows=24828 width=16) (actual time=20130.902..26827.400 rows=24106 loops=1) Buffers: shared hit=692411 read=260751 dirtied=2809 written=3953 -> Hash Join (cost=501788.40..2184080.42 rows=24855 width=16) (actual time=20130.859..26556.397 rows=24106 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=619987 read=260751 dirtied=2809 written=3953 -> Nested Loop (cost=0.00..1679993.69 rows=409957 width=16) (actual time=0.371..5264.765 rows=395218 loops=1) Buffers: shared hit=234034 read=231333 dirtied=2784 written=1151 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..46901.09 rows=13520 width=4) (actual time=0.285..202.052 rows=13196 loops=1) Index Cond: (p_type = 'MEDIUM ANODIZED COPPER'::text) Heap Fetches: 13196 Buffers: shared hit=1 read=11438 written=64 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..120.48 rows=31 width=20) (actual time=0.036..0.371 rows=30 loops=13196) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=234033 read=219895 dirtied=2784 written=1087 -> Hash (cost=490295.72..490295.72 rows=919414 width=8) (actual time=20129.624..20129.624 rows=912009 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35626kB Buffers: shared hit=385950 read=29418 dirtied=25 written=2802 -> Hash Join (cost=138852.56..490295.72 rows=919414 width=8) (actual time=4163.991..19515.945 rows=912009 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=385950 read=29418 dirtied=25 written=2802 -> Bitmap Heap Scan on orders (cost=99821.94..424831.96 rows=4597068 width=12) (actual time=3176.554..6703.552 rows=4561778 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=241652 read=27567 dirtied=25 written=2474 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..98672.67 rows=4597068 width=0) (actual time=3078.476..3078.476 rows=4607485 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=781 read=12384 written=2363 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=986.328..986.328 rows=299493 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10530kB Buffers: shared hit=144298 read=1851 written=328 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=26.247..854.984 rows=299493 loops=1) Buffers: shared hit=144298 read=1851 written=328 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.028..0.080 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..0.016 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.014..0.014 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=0.011..0.012 rows=1 loops=1) Filter: (r_name = 'AFRICA'::bpchar) Rows Removed by Filter: 4 Buffers: shared hit=1 -> Bitmap Heap Scan on customer (cost=905.09..6455.63 rows=60000 width=8) (actual time=24.598..157.690 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=144296 read=1851 written=328 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=16.558..16.558 rows=59899 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=11 read=822 written=124 -> Index Scan using pk_supplier on supplier (cost=0.00..0.28 rows=1 width=8) (actual time=0.009..0.010 rows=1 loops=24106) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72424 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.003..0.003 rows=1 loops=24106) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48212 Total runtime: 27028.798 ms (64 rows) COMMIT; COMMIT