BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'UNITED KINGDOM' 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 = 'EUROPE' 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=1720808.85..1720810.68 rows=730 width=38) (actual time=11312.186..11312.187 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=1975851 read=292776 dirtied=462 written=10 -> HashAggregate (cost=1720761.36..1720774.14 rows=730 width=38) (actual time=11312.128..11312.130 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=1975848 read=292776 dirtied=462 written=10 -> Hash Join (cost=39444.58..1720278.64 rows=24136 width=38) (actual time=1366.954..11271.326 rows=24268 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=1975848 read=292776 dirtied=462 written=10 -> Nested Loop (cost=39443.02..1719824.53 rows=24136 width=16) (actual time=1366.879..11230.701 rows=24268 loops=1) Buffers: shared hit=1975844 read=292776 dirtied=462 written=10 -> Hash Join (cost=39442.72..1712028.99 rows=24160 width=16) (actual time=1366.853..11033.847 rows=24268 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1902912 read=292776 dirtied=462 written=10 -> Nested Loop (cost=412.04..1672303.70 rows=120802 width=20) (actual time=7.743..9547.155 rows=120510 loops=1) Buffers: shared hit=1792477 read=257035 dirtied=462 written=4 -> Nested Loop (cost=411.60..1477088.62 rows=398689 width=16) (actual time=7.161..3793.273 rows=396016 loops=1) Buffers: shared hit=271304 read=192022 dirtied=342 written=3 -> Bitmap Heap Scan on part (cost=411.04..28006.04 rows=13240 width=4) (actual time=7.087..132.173 rows=13188 loops=1) Recheck Cond: ((p_type)::text = 'PROMO BURNISHED STEEL'::text) Heap Blocks: exact=11313 Buffers: shared hit=4737 read=6658 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..407.73 rows=13240 width=0) (actual time=4.788..4.788 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..109.14 rows=31 width=20) (actual time=0.026..0.267 rows=30 loops=13188) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=266567 read=185364 dirtied=342 written=3 -> 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=396016) 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=1521173 read=65013 dirtied=120 written=1 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=1355.703..1355.703 rows=300963 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14677kB Buffers: shared hit=110435 read=35741 written=6 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=21.380..1229.905 rows=300963 loops=1) Buffers: shared hit=110435 read=35741 written=6 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.047..0.101 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=0.008..0.026 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.019..0.019 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=0.012..0.013 rows=1 loops=1) Filter: (r_name = 'EUROPE'::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=21.565..233.835 rows=60193 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145336 Buffers: shared hit=110433 read=35741 written=6 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=13.858..13.858 rows=60193 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=6 read=832 written=3 -> 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=24268) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72932 -> 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: 6.947 ms Execution time: 11313.738 ms (68 rows) COMMIT; COMMIT