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 = 'SMALL PLATED BRASS' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2139488.05..2139489.88 rows=733 width=38) (actual time=39698.623..39698.623 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=686877 read=315592 dirtied=1093 written=87 -> HashAggregate (cost=2139440.34..2139453.17 rows=733 width=38) (actual time=39698.534..39698.535 rows=2 loops=1) Buffers: shared hit=686874 read=315592 dirtied=1093 written=87 -> Nested Loop (cost=498476.06..2138962.48 rows=23893 width=38) (actual time=28370.530..39617.721 rows=24397 loops=1) Buffers: shared hit=686874 read=315592 dirtied=1093 written=87 -> Nested Loop (cost=498476.06..2132148.20 rows=23893 width=16) (actual time=28370.452..39283.460 rows=24397 loops=1) Buffers: shared hit=638080 read=315592 dirtied=1093 written=87 -> Hash Join (cost=498476.06..2125190.49 rows=23893 width=16) (actual time=28370.391..38725.556 rows=24397 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=564757 read=315592 dirtied=1093 written=87 -> Nested Loop (cost=0.00..1624512.32 rows=392636 width=16) (actual time=0.441..9014.450 rows=398309 loops=1) Buffers: shared hit=274381 read=192306 dirtied=1093 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..45379.78 rows=13013 width=4) (actual time=0.385..196.331 rows=13276 loops=1) Index Cond: (p_type = 'SMALL PLATED BRASS'::text) Heap Fetches: 13276 Buffers: shared hit=8831 read=2564 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..121.04 rows=31 width=20) (actual time=0.072..0.647 rows=30 loops=13276) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=265550 read=189742 dirtied=1093 -> Hash (cost=486997.81..486997.81 rows=918260 width=8) (actual time=28368.951..28368.951 rows=913326 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35677kB Buffers: shared hit=290373 read=123286 written=87 -> Hash Join (cost=136941.36..486997.81 rows=918260 width=8) (actual time=7306.816..27613.981 rows=913326 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=290373 read=123286 written=87 -> Bitmap Heap Scan on orders (cost=97910.74..421567.22 rows=4591299 width=12) (actual time=4025.296..11071.441 rows=4561664 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=180241 read=87180 written=57 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..96762.91 rows=4591299 width=0) (actual time=3907.568..3907.568 rows=4584480 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared read=12634 written=2 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=3281.235..3281.235 rows=300270 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10557kB Buffers: shared hit=110132 read=36106 written=30 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=47.030..3064.924 rows=300270 loops=1) Buffers: shared hit=110132 read=36106 written=30 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.040..0.104 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=0.006..0.025 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.018..0.018 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=0.016..0.017 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=42.032..590.598 rows=60054 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=110130 read=36106 written=30 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=30.019..30.019 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=0.020..0.020 rows=1 loops=24397) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=73323 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.010..0.010 rows=1 loops=24397) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48794 Total runtime: 39719.361 ms (64 rows) COMMIT; COMMIT