BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'ALGERIA' 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 BRUSHED COPPER' ) as all_nations group by o_year order by o_year; QUERY PLAN ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1711895.98..1711897.81 rows=730 width=38) (actual time=11704.976..11704.976 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=1942232 read=346040 dirtied=1245 written=230 -> HashAggregate (cost=1711848.49..1711861.26 rows=730 width=38) (actual time=11704.923..11704.924 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=1942229 read=346040 dirtied=1245 written=230 -> Hash Join (cost=39439.86..1711367.75 rows=24037 width=38) (actual time=1097.532..11665.060 rows=24388 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=1942229 read=346040 dirtied=1245 written=230 -> Nested Loop (cost=39438.29..1710915.49 rows=24037 width=16) (actual time=1097.474..11630.123 rows=24388 loops=1) Buffers: shared hit=1942225 read=346040 dirtied=1245 written=230 -> Hash Join (cost=39438.00..1703151.59 rows=24062 width=16) (actual time=1097.453..11428.312 rows=24388 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1868944 read=346040 dirtied=1245 written=230 -> Nested Loop (cost=407.32..1663429.11 rows=120311 width=20) (actual time=6.913..10264.904 rows=121346 loops=1) Buffers: shared hit=1758405 read=310431 dirtied=1245 written=230 -> Nested Loop (cost=406.88..1469004.02 rows=397069 width=16) (actual time=6.815..4261.857 rows=399589 loops=1) Buffers: shared hit=247412 read=220880 dirtied=1228 written=163 -> Bitmap Heap Scan on part (cost=406.32..27888.46 rows=13147 width=4) (actual time=6.751..148.663 rows=13305 loops=1) Recheck Cond: ((p_type)::text = 'MEDIUM BRUSHED COPPER'::text) Heap Blocks: exact=11358 Buffers: shared hit=2921 read=8520 written=4 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..403.03 rows=13147 width=0) (actual time=4.663..4.663 rows=13305 loops=1) Index Cond: ((p_type)::text = 'MEDIUM BRUSHED COPPER'::text) Buffers: shared read=83 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.56..109.31 rows=31 width=20) (actual time=0.029..0.299 rows=30 loops=13305) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=244491 read=212360 dirtied=1228 written=159 -> Index Scan using pk_orders on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.014..0.014 rows=0 loops=399589) Index Cond: (o_orderkey = lineitem.l_orderkey) Filter: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Rows Removed by Filter: 1 Buffers: shared hit=1510993 read=89551 dirtied=17 written=67 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=1086.986..1086.986 rows=299493 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14626kB Buffers: shared hit=110539 read=35609 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=19.063..995.440 rows=299493 loops=1) Buffers: shared hit=110539 read=35609 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.045..0.084 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=0.016..0.016 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=0.010..0.012 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=18.465..188.013 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145314 Buffers: shared hit=110537 read=35609 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=12.014..12.014 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..0.007 rows=1 loops=24388) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=73281 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.024..0.024 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=0.006..0.008 rows=25 loops=1) Buffers: shared hit=1 Planning time: 6.967 ms Execution time: 11705.814 ms (68 rows) COMMIT; COMMIT