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 = 'MEDIUM ANODIZED STEEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2191822.86..2191824.70 rows=733 width=38) (actual time=33589.976..33589.977 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=721894 read=286089 dirtied=2702 written=104 -> HashAggregate (cost=2191775.15..2191787.98 rows=733 width=38) (actual time=33589.888..33589.890 rows=2 loops=1) Buffers: shared hit=721891 read=286089 dirtied=2702 written=104 -> Nested Loop (cost=502090.26..2191279.17 rows=24799 width=38) (actual time=24140.451..33511.966 rows=24557 loops=1) Buffers: shared hit=721891 read=286089 dirtied=2702 written=104 -> Nested Loop (cost=502090.26..2184206.50 rows=24799 width=16) (actual time=24140.365..33248.840 rows=24557 loops=1) Buffers: shared hit=672777 read=286089 dirtied=2702 written=104 -> Hash Join (cost=502090.26..2176984.98 rows=24799 width=16) (actual time=24140.326..32735.152 rows=24557 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=598979 read=286082 dirtied=2702 written=104 -> Nested Loop (cost=0.00..1672609.12 rows=407521 width=16) (actual time=0.460..7368.112 rows=399549 loops=1) Buffers: shared hit=308775 read=161185 dirtied=2450 written=92 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..46699.46 rows=13453 width=4) (actual time=0.367..350.965 rows=13333 loops=1) Index Cond: (p_type = 'MEDIUM ANODIZED STEEL'::text) Heap Fetches: 13333 Buffers: shared hit=2 read=11510 written=5 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..120.55 rows=31 width=20) (actual time=0.058..0.509 rows=30 loops=13333) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=308773 read=149675 dirtied=2450 written=87 -> Hash (cost=490566.34..490566.34 rows=921914 width=8) (actual time=24137.996..24137.996 rows=911892 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35621kB Buffers: shared hit=290201 read=124897 dirtied=252 written=12 -> Hash Join (cost=139116.72..490566.34 rows=921914 width=8) (actual time=3842.669..23312.029 rows=911892 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=290201 read=124897 dirtied=252 written=12 -> Bitmap Heap Scan on orders (cost=100086.10..425030.68 rows=4609572 width=12) (actual time=2397.256..8691.606 rows=4561673 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=180154 read=88795 dirtied=252 written=12 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..98933.71 rows=4609572 width=0) (actual time=2232.216..2232.216 rows=4602796 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared read=13148 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=1444.871..1444.871 rows=299493 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10530kB Buffers: shared hit=110047 read=36102 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=41.355..1337.197 rows=299493 loops=1) Buffers: shared hit=110047 read=36102 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.038..0.107 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..0.024 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..0.016 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=25.553..253.916 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=110045 read=36102 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=17.184..17.184 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=0.018..0.018 rows=1 loops=24557) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=73798 read=7 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.007..0.007 rows=1 loops=24557) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=49114 Total runtime: 33606.116 ms (64 rows) COMMIT; COMMIT