BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'PERU' 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 = 'AMERICA' and s_nationkey = n2.n_nationkey and o_orderdate between date '1995-01-01' and date '1996-12-31' and p_type = 'SMALL PLATED STEEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1787394.82..1787396.65 rows=729 width=38) (actual time=10922.549..10922.550 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=2029517 read=261541 dirtied=730 written=319 -> HashAggregate (cost=1787347.40..1787360.16 rows=729 width=38) (actual time=10922.487..10922.488 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=2029514 read=261541 dirtied=730 written=319 -> Hash Join (cost=39461.33..1786842.40 rows=25250 width=38) (actual time=883.409..10883.405 rows=24221 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=2029514 read=261541 dirtied=730 written=319 -> Nested Loop (cost=39459.77..1786367.40 rows=25250 width=16) (actual time=883.351..10850.810 rows=24221 loops=1) Buffers: shared hit=2029510 read=261541 dirtied=730 written=319 -> Hash Join (cost=39459.47..1778220.16 rows=25250 width=16) (actual time=883.330..10661.424 rows=24221 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1956716 read=261541 dirtied=730 written=319 -> Nested Loop (cost=428.79..1738463.53 rows=126252 width=20) (actual time=7.287..9702.769 rows=121380 loops=1) Buffers: shared hit=1817015 read=255305 dirtied=730 written=300 -> Nested Loop (cost=428.35..1534208.26 rows=417152 width=16) (actual time=7.219..4068.543 rows=400456 loops=1) Buffers: shared hit=278535 read=189835 dirtied=491 written=197 -> Bitmap Heap Scan on part (cost=427.79..28746.74 rows=13853 width=4) (actual time=7.144..190.861 rows=13335 loops=1) Recheck Cond: ((p_type)::text = 'SMALL PLATED STEEL'::text) Heap Blocks: exact=11425 Buffers: shared hit=510 read=10984 written=12 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..424.32 rows=13853 width=0) (actual time=4.880..4.880 rows=13335 loops=1) Index Cond: ((p_type)::text = 'SMALL PLATED STEEL'::text) Buffers: shared read=69 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.56..108.36 rows=31 width=20) (actual time=0.028..0.281 rows=30 loops=13335) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=278025 read=178851 dirtied=491 written=185 -> Index Scan using pk_orders on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.013..0.014 rows=0 loops=400456) 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=1538480 read=65470 dirtied=239 written=103 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=872.437..872.437 rows=299436 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14624kB Buffers: shared hit=139701 read=6236 written=19 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=21.910..777.391 rows=299436 loops=1) Buffers: shared hit=139701 read=6236 written=19 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.048..0.078 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=0.009..0.020 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.020..0.020 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 = 'AMERICA'::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=18.123..145.375 rows=59887 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145102 Buffers: shared hit=139699 read=6236 written=19 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=11.927..11.927 rows=59887 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=8 read=825 -> Index Scan using pk_supplier on supplier (cost=0.29..0.31 rows=1 width=8) (actual time=0.006..0.007 rows=1 loops=24221) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72794 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.021..0.021 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: 7.982 ms Execution time: 10923.338 ms (68 rows) COMMIT; COMMIT