BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'MOZAMBIQUE' 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 = 'SMALL ANODIZED TIN' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2209047.07..2209048.90 rows=730 width=38) (actual time=26125.333..26125.334 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=757340 read=253327 dirtied=2717 written=61 -> HashAggregate (cost=2208999.58..2209012.35 rows=730 width=38) (actual time=26125.270..26125.273 rows=2 loops=1) Buffers: shared hit=757337 read=253327 dirtied=2717 written=61 -> Nested Loop (cost=500842.04..2208500.08 rows=24975 width=38) (actual time=19023.414..26066.900 rows=24688 loops=1) Buffers: shared hit=757337 read=253327 dirtied=2717 written=61 -> Nested Loop (cost=500842.04..2201377.21 rows=24975 width=16) (actual time=19023.309..25932.116 rows=24688 loops=1) Buffers: shared hit=707961 read=253327 dirtied=2717 written=61 -> Hash Join (cost=500842.04..2194096.57 rows=25002 width=16) (actual time=19023.248..25650.330 rows=24688 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=633782 read=253327 dirtied=2717 written=61 -> Nested Loop (cost=0.00..1690942.61 rows=412379 width=16) (actual time=0.274..5408.283 rows=401927 loops=1) Buffers: shared hit=234897 read=237380 dirtied=2464 written=61 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..47218.96 rows=13627 width=4) (actual time=0.220..157.019 rows=13380 loops=1) Index Cond: (p_type = 'SMALL ANODIZED TIN'::text) Heap Fetches: 13380 Buffers: shared hit=3671 read=7822 written=4 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..120.31 rows=31 width=20) (actual time=0.036..0.379 rows=30 loops=13380) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=231226 read=229558 dirtied=2464 written=57 -> Hash (cost=489372.08..489372.08 rows=917597 width=8) (actual time=19021.897..19021.897 rows=911872 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35620kB Buffers: shared hit=398882 read=15947 dirtied=253 -> Hash Join (cost=138623.43..489372.08 rows=917597 width=8) (actual time=4011.890..18566.263 rows=911872 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=398882 read=15947 dirtied=253 -> Bitmap Heap Scan on orders (cost=99592.81..423960.55 rows=4587983 width=12) (actual time=3162.249..6838.787 rows=4561632 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=253571 read=15109 dirtied=253 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..98445.81 rows=4587983 width=0) (actual time=2933.636..2933.636 rows=4598186 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared read=13132 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=848.792..848.792 rows=299493 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10530kB Buffers: shared hit=145311 read=838 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=22.019..747.428 rows=299493 loops=1) Buffers: shared hit=145311 read=838 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.023..0.060 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=0.011..0.011 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=0.008..0.009 rows=1 loops=1) Filter: (r_name = 'AFRICA'::bpchar) Rows Removed by Filter: 4 Buffers: shared hit=1 -> Bitmap Heap Scan on customer (cost=905.09..6455.63 rows=60000 width=8) (actual time=21.332..137.238 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=145309 read=838 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=14.116..14.116 rows=59899 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=7 read=826 -> Index Scan using pk_supplier on supplier (cost=0.00..0.28 rows=1 width=8) (actual time=0.009..0.010 rows=1 loops=24688) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=74179 -> 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=24688) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=49376 Total runtime: 26142.411 ms (64 rows) COMMIT; COMMIT