BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'ETHIOPIA' 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 = 'ECONOMY ANODIZED COPPER' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2231252.90..2231254.72 rows=729 width=38) (actual time=29014.454..29014.455 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=793817 read=225946 dirtied=416 -> HashAggregate (cost=2231205.47..2231218.23 rows=729 width=38) (actual time=29014.379..29014.381 rows=2 loops=1) Buffers: shared hit=793814 read=225946 dirtied=416 -> Nested Loop (cost=495764.03..2230699.77 rows=25285 width=38) (actual time=20034.430..28940.736 rows=25126 loops=1) Buffers: shared hit=793814 read=225946 dirtied=416 -> Nested Loop (cost=495764.03..2223488.49 rows=25285 width=16) (actual time=20034.345..28738.001 rows=25126 loops=1) Buffers: shared hit=743562 read=225946 dirtied=416 -> Hash Join (cost=495764.03..2216115.81 rows=25318 width=16) (actual time=20034.287..28327.378 rows=25126 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=668047 read=225946 dirtied=416 -> Nested Loop (cost=0.00..1718006.85 rows=418351 width=16) (actual time=0.362..6854.746 rows=411271 loops=1) Buffers: shared hit=256468 read=224635 dirtied=416 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..48007.43 rows=13893 width=4) (actual time=0.286..179.871 rows=13678 loops=1) Index Cond: (p_type = 'ECONOMY ANODIZED COPPER'::text) Heap Fetches: 13678 Buffers: shared hit=7227 read=4515 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..119.89 rows=31 width=20) (actual time=0.046..0.471 rows=30 loops=13678) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=249241 read=220120 dirtied=416 -> Hash (cost=484371.31..484371.31 rows=911418 width=8) (actual time=20032.311..20032.311 rows=911910 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35622kB Buffers: shared hit=411576 read=1311 -> Hash Join (cost=135530.69..484371.31 rows=911418 width=8) (actual time=4039.334..19554.466 rows=911910 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=411576 read=1311 -> Bitmap Heap Scan on orders (cost=96500.07..419137.42 rows=4557090 width=12) (actual time=2864.683..6683.138 rows=4561773 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=265427 read=1311 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..95360.80 rows=4557090 width=0) (actual time=2715.960..2715.960 rows=4575464 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=12457 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=1173.829..1173.829 rows=299493 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10530kB Buffers: shared hit=146149 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=26.620..1006.494 rows=299493 loops=1) Buffers: shared hit=146149 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.041..0.093 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=0.008..0.020 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.019..0.019 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 = '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=26.243..183.685 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=146147 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=17.122..17.122 rows=59899 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=833 -> Index Scan using pk_supplier on supplier (cost=0.00..0.28 rows=1 width=8) (actual time=0.014..0.014 rows=1 loops=25126) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=75515 -> 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=25126) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=50252 Total runtime: 29027.309 ms (64 rows) COMMIT; COMMIT