BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'KENYA' 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 PLATED TIN' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2190906.10..2190907.92 rows=728 width=38) (actual time=46688.499..46688.499 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=796143 read=212175 dirtied=806 written=28 -> HashAggregate (cost=2190858.75..2190871.49 rows=728 width=38) (actual time=46688.425..46688.428 rows=2 loops=1) Buffers: shared hit=796140 read=212175 dirtied=806 written=28 -> Nested Loop (cost=496018.70..2190366.59 rows=24608 width=38) (actual time=28426.632..46591.299 rows=24488 loops=1) Buffers: shared hit=796140 read=212175 dirtied=806 written=28 -> Nested Loop (cost=496018.70..2183348.39 rows=24608 width=16) (actual time=28426.547..46194.230 rows=24488 loops=1) Buffers: shared hit=747164 read=212175 dirtied=806 written=28 -> Hash Join (cost=496018.70..2176180.14 rows=24616 width=16) (actual time=28426.472..45106.052 rows=24488 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=673568 read=212175 dirtied=806 written=28 -> Nested Loop (cost=0.00..1677878.69 rows=407319 width=16) (actual time=1.167..15469.021 rows=403489 loops=1) Buffers: shared hit=274373 read=198198 dirtied=806 written=28 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..46876.68 rows=13513 width=4) (actual time=0.682..571.161 rows=13457 loops=1) Index Cond: (p_type = 'STANDARD PLATED TIN'::text) Heap Fetches: 13457 Buffers: shared hit=1909 read=9660 written=2 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..120.39 rows=31 width=20) (actual time=0.128..1.089 rows=30 loops=13457) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=272464 read=188538 dirtied=806 written=26 -> Hash (cost=484630.62..484630.62 rows=911046 width=8) (actual time=28424.472..28424.472 rows=911915 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35622kB Buffers: shared hit=399192 read=13977 -> Hash Join (cost=135575.62..484630.62 rows=911046 width=8) (actual time=4925.761..27540.219 rows=911915 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=399192 read=13977 -> Bitmap Heap Scan on orders (cost=96545.00..419407.43 rows=4555229 width=12) (actual time=3245.225..12964.413 rows=4561668 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=253888 read=13132 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..95406.19 rows=4555229 width=0) (actual time=3072.772..3072.772 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=1680.007..1680.007 rows=299493 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10530kB Buffers: shared hit=145304 read=845 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=32.663..1500.285 rows=299493 loops=1) Buffers: shared hit=145304 read=845 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.038..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=0.007..0.015 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=0.014..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=32.841..280.892 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=145302 read=845 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=23.093..23.093 rows=59899 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=8 read=825 -> Index Scan using pk_supplier on supplier (cost=0.00..0.28 rows=1 width=8) (actual time=0.041..0.042 rows=1 loops=24488) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=73596 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.012..0.012 rows=1 loops=24488) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48976 Total runtime: 46701.374 ms (64 rows) COMMIT; COMMIT