BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'CHINA' 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 = 'ASIA' and s_nationkey = n2.n_nationkey and o_orderdate between date '1995-01-01' and date '1996-12-31' and p_type = 'ECONOMY POLISHED NICKEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2206833.31..2206835.14 rows=730 width=38) (actual time=25502.227..25502.228 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=840320 read=173986 dirtied=4198 written=84 -> HashAggregate (cost=2206785.82..2206798.59 rows=730 width=38) (actual time=25502.132..25502.134 rows=2 loops=1) Buffers: shared hit=840317 read=173986 dirtied=4198 written=84 -> Nested Loop (cost=502706.70..2206286.06 rows=24988 width=38) (actual time=19048.485..25444.593 rows=24491 loops=1) Buffers: shared hit=840317 read=173986 dirtied=4198 written=84 -> Nested Loop (cost=502706.70..2199159.48 rows=24988 width=16) (actual time=19048.406..25304.221 rows=24491 loops=1) Buffers: shared hit=791335 read=173986 dirtied=4198 written=84 -> Hash Join (cost=502706.70..2191875.07 rows=25015 width=16) (actual time=19048.356..25014.132 rows=24491 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=717717 read=173986 dirtied=4198 written=84 -> Nested Loop (cost=0.00..1686855.25 rows=412595 width=16) (actual time=0.480..4641.239 rows=403422 loops=1) Buffers: shared hit=326672 read=149039 dirtied=4198 written=63 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..47082.14 rows=13580 width=4) (actual time=0.384..193.233 rows=13440 loops=1) Index Cond: (p_type = 'ECONOMY POLISHED NICKEL'::text) Heap Fetches: 13440 Buffers: shared hit=1859 read=9631 written=3 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..120.44 rows=31 width=20) (actual time=0.035..0.318 rows=30 loops=13440) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=324813 read=139408 dirtied=4198 written=60 -> Hash (cost=491191.32..491191.32 rows=921230 width=8) (actual time=19046.140..19046.140 rows=912364 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35640kB Buffers: shared hit=391042 read=24947 written=21 -> Hash Join (cost=139053.67..491191.32 rows=921230 width=8) (actual time=3809.012..18489.353 rows=912364 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=391042 read=24947 written=21 -> Bitmap Heap Scan on orders (cost=100023.05..425675.33 rows=4606152 width=12) (actual time=2945.652..6636.799 rows=4557055 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=245641 read=24110 written=21 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..98871.51 rows=4606152 width=0) (actual time=2842.646..2842.646 rows=4616605 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared read=13191 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=862.606..862.606 rows=300270 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10557kB Buffers: shared hit=145401 read=837 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=22.904..749.899 rows=300270 loops=1) Buffers: shared hit=145401 read=837 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.028..0.072 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=0.004..0.013 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.013..0.013 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=0.010..0.011 rows=1 loops=1) Filter: (r_name = 'ASIA'::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=21.659..136.904 rows=60054 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=145399 read=837 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=14.440..14.440 rows=60054 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=5 read=831 -> Index Scan using pk_supplier on supplier (cost=0.00..0.28 rows=1 width=8) (actual time=0.010..0.010 rows=1 loops=24491) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=73618 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.003..0.003 rows=1 loops=24491) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48982 Total runtime: 25514.544 ms (64 rows) COMMIT; COMMIT