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 = 'STANDARD BRUSHED BRASS' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2219082.71..2219084.53 rows=731 width=38) (actual time=28317.679..28317.679 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=751350 read=247112 dirtied=679 written=3 -> HashAggregate (cost=2219035.14..2219047.93 rows=731 width=38) (actual time=28317.592..28317.595 rows=2 loops=1) Buffers: shared hit=751347 read=247112 dirtied=679 written=3 -> Nested Loop (cost=496398.52..2218531.56 rows=25179 width=38) (actual time=21068.507..28253.420 rows=24222 loops=1) Buffers: shared hit=751347 read=247112 dirtied=679 written=3 -> Nested Loop (cost=496398.52..2211350.51 rows=25179 width=16) (actual time=21068.422..28081.568 rows=24222 loops=1) Buffers: shared hit=702903 read=247112 dirtied=679 written=3 -> Hash Join (cost=496398.52..2204018.31 rows=25179 width=16) (actual time=21068.363..27758.286 rows=24222 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=630088 read=247112 dirtied=679 written=3 -> Nested Loop (cost=0.00..1705294.28 rows=414744 width=16) (actual time=0.541..5677.258 rows=396874 loops=1) Buffers: shared hit=259460 read=204850 dirtied=413 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..47653.37 rows=13773 width=4) (actual time=0.450..214.627 rows=13225 loops=1) Index Cond: (p_type = 'STANDARD BRUSHED BRASS'::text) Heap Fetches: 13225 Buffers: shared hit=1911 read=9468 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..120.04 rows=31 width=20) (actual time=0.039..0.398 rows=30 loops=13225) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=257549 read=195382 dirtied=413 -> Hash (cost=484970.08..484970.08 rows=914275 width=8) (actual time=21066.793..21066.793 rows=911910 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35622kB Buffers: shared hit=370625 read=42262 dirtied=266 written=3 -> Hash Join (cost=135833.09..484970.08 rows=914275 width=8) (actual time=4588.407..20486.995 rows=911910 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=370625 read=42262 dirtied=266 written=3 -> Bitmap Heap Scan on orders (cost=96802.47..419654.06 rows=4571373 width=12) (actual time=3016.500..7679.318 rows=4561773 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=224476 read=42262 dirtied=266 written=3 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..95659.63 rows=4571373 width=0) (actual time=2881.764..2881.764 rows=4575464 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=3 read=12454 written=3 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=1571.490..1571.490 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=30.416..1364.765 rows=299493 loops=1) Buffers: shared hit=146149 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.038..0.108 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=0.006..0.023 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=0.013..0.015 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=30.358..251.401 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=19.820..19.820 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=0.011..0.011 rows=1 loops=24222) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72815 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.004..0.004 rows=1 loops=24222) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48444 Total runtime: 28332.476 ms (64 rows) COMMIT; COMMIT