BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'MOZAMBIQUE' 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 = 'PROMO BURNISHED STEEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1718111.72..1718113.54 rows=729 width=38) (actual time=13143.459..13143.459 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=1660386 read=329460 dirtied=391 written=5052 -> HashAggregate (cost=1718064.29..1718077.05 rows=729 width=38) (actual time=13143.385..13143.386 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=1660383 read=329460 dirtied=391 written=5052 -> Hash Join (cost=39444.48..1717583.35 rows=24047 width=38) (actual time=1701.160..13097.706 rows=24119 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=1660383 read=329460 dirtied=391 written=5052 -> Nested Loop (cost=39442.91..1717130.91 rows=24047 width=16) (actual time=1701.090..13054.047 rows=24119 loops=1) Buffers: shared hit=1660379 read=329460 dirtied=391 written=5052 -> Hash Join (cost=39442.62..1709371.82 rows=24047 width=16) (actual time=1701.035..12842.148 rows=24119 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1588133 read=329207 dirtied=391 written=5052 -> Nested Loop (cost=411.94..1669649.78 rows=120235 width=20) (actual time=9.637..11044.123 rows=120405 loops=1) Buffers: shared hit=1458368 read=312824 dirtied=391 written=5052 -> Nested Loop (cost=411.50..1475210.23 rows=397112 width=16) (actual time=8.500..5324.370 rows=395680 loops=1) Buffers: shared hit=238020 read=224321 dirtied=391 written=3754 -> Bitmap Heap Scan on part (cost=410.94..27991.24 rows=13227 width=4) (actual time=8.411..114.732 rows=13188 loops=1) Recheck Cond: ((p_type)::text = 'PROMO BURNISHED STEEL'::text) Heap Blocks: exact=11313 Buffers: shared hit=7385 read=4010 written=113 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..407.63 rows=13227 width=0) (actual time=6.021..6.021 rows=13188 loops=1) Index Cond: ((p_type)::text = 'PROMO BURNISHED STEEL'::text) Buffers: shared read=82 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.56..109.10 rows=31 width=20) (actual time=0.035..0.383 rows=30 loops=13188) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=230635 read=220311 dirtied=391 written=3641 -> Index Scan using orders_o_orderkey_o_orderdate_idx on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.014..0.014 rows=0 loops=395680) Index Cond: ((o_orderkey = lineitem.l_orderkey) AND (o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=1220348 read=88503 written=1298 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=1687.013..1687.013 rows=299493 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14626kB Buffers: shared hit=129765 read=16383 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=37.548..1569.943 rows=299493 loops=1) Buffers: shared hit=129765 read=16383 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.094..0.158 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=0.014..0.028 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.035..0.035 rows=1 loops=1) Buckets: 1024 Batches: 1 Memory Usage: 9kB Buffers: shared hit=1 -> Seq Scan on region (cost=0.00..1.06 rows=1 width=4) (actual time=0.024..0.027 rows=1 loops=1) Filter: (r_name = 'AFRICA'::bpchar) Rows Removed by Filter: 4 Buffers: shared hit=1 -> Bitmap Heap Scan on customer (cost=905.11..6455.64 rows=60000 width=8) (actual time=27.890..300.212 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145314 Buffers: shared hit=129763 read=16383 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=19.661..19.661 rows=59899 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=7 read=825 -> Index Scan using pk_supplier on supplier (cost=0.29..0.31 rows=1 width=8) (actual time=0.007..0.008 rows=1 loops=24119) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72246 read=253 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.023..0.023 rows=25 loops=1) Buckets: 1024 Batches: 1 Memory Usage: 10kB Buffers: shared hit=1 -> Seq Scan on nation n2 (cost=0.00..1.25 rows=25 width=30) (actual time=0.004..0.007 rows=25 loops=1) Buffers: shared hit=1 Planning time: 6.930 ms Execution time: 13144.605 ms (66 rows) COMMIT; COMMIT