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 BURNISHED TIN' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2172567.89..2172569.71 rows=729 width=38) (actual time=28662.766..28662.766 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=796086 read=205510 dirtied=1275 written=792 -> HashAggregate (cost=2172520.47..2172533.23 rows=729 width=38) (actual time=28662.690..28662.693 rows=2 loops=1) Buffers: shared hit=796083 read=205510 dirtied=1275 written=792 -> Nested Loop (cost=496304.93..2172034.31 rows=24308 width=38) (actual time=21233.382..28600.455 rows=24269 loops=1) Buffers: shared hit=796083 read=205510 dirtied=1275 written=792 -> Nested Loop (cost=496304.93..2165101.67 rows=24308 width=16) (actual time=21233.308..28449.846 rows=24269 loops=1) Buffers: shared hit=747545 read=205510 dirtied=1275 written=792 -> Hash Join (cost=496304.93..2158013.79 rows=24340 width=16) (actual time=21233.272..28138.078 rows=24269 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=674586 read=205510 dirtied=1275 written=792 -> Nested Loop (cost=0.00..1659454.53 rows=402186 width=16) (actual time=0.314..5571.281 rows=397993 loops=1) Buffers: shared hit=276880 read=190044 dirtied=1275 written=512 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..46361.77 rows=13340 width=4) (actual time=0.243..230.755 rows=13268 loops=1) Index Cond: (p_type = 'MEDIUM BURNISHED TIN'::text) Heap Fetches: 13268 Buffers: shared hit=2 read=11413 written=31 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..120.61 rows=31 width=20) (actual time=0.041..0.388 rows=30 loops=13268) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=276878 read=178631 dirtied=1275 written=481 -> Hash (cost=484900.87..484900.87 rows=912325 width=8) (actual time=21231.847..21231.847 rows=911004 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35587kB Buffers: shared hit=397703 read=15466 written=280 -> Hash Join (cost=135713.17..484900.87 rows=912325 width=8) (actual time=4420.347..19861.496 rows=911004 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=397703 read=15466 written=280 -> Bitmap Heap Scan on orders (cost=96682.55..419640.91 rows=4561624 width=12) (actual time=3216.102..7261.486 rows=4557142 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=252499 read=14521 written=280 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..95542.14 rows=4561624 width=0) (actual time=3089.856..3089.856 rows=4579958 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared read=12486 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=1203.951..1203.951 rows=299493 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10530kB Buffers: shared hit=145204 read=945 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=29.075..1039.276 rows=299493 loops=1) Buffers: shared hit=145204 read=945 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.027..0.079 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..0.018 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..0.010 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=27.730..189.530 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=145202 read=945 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=18.732..18.732 rows=59899 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=7 read=826 -> Index Scan using pk_supplier on supplier (cost=0.00..0.28 rows=1 width=8) (actual time=0.011..0.011 rows=1 loops=24269) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72959 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.003..0.004 rows=1 loops=24269) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48538 Total runtime: 28682.712 ms (64 rows) COMMIT; COMMIT