BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'ETHIOPIA' 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 = 'PROMO BURNISHED COPPER' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2207191.65..2207193.47 rows=729 width=38) (actual time=25740.996..25740.997 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=812451 read=187063 dirtied=613 written=9111 -> HashAggregate (cost=2207144.23..2207156.98 rows=729 width=38) (actual time=25740.936..25740.937 rows=2 loops=1) Buffers: shared hit=812448 read=187063 dirtied=613 written=9111 -> Nested Loop (cost=494549.32..2206647.51 rows=24836 width=38) (actual time=20011.552..25683.488 rows=24245 loops=1) Buffers: shared hit=812448 read=187063 dirtied=613 written=9111 -> Nested Loop (cost=494549.32..2199564.28 rows=24836 width=16) (actual time=20011.480..25541.721 rows=24245 loops=1) Buffers: shared hit=763958 read=187063 dirtied=613 written=9111 -> Hash Join (cost=494549.32..2192322.34 rows=24869 width=16) (actual time=20011.439..25247.663 rows=24245 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=691097 read=187060 dirtied=613 written=9111 -> Nested Loop (cost=0.00..1695469.73 rows=410919 width=16) (actual time=0.215..4307.900 rows=398469 loops=1) Buffers: shared hit=356339 read=109688 dirtied=613 written=6282 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..47395.83 rows=13687 width=4) (actual time=0.198..220.773 rows=13309 loops=1) Index Cond: (p_type = 'PROMO BURNISHED COPPER'::text) Heap Fetches: 13309 Buffers: shared hit=1444 read=10087 written=618 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..120.10 rows=31 width=20) (actual time=0.036..0.293 rows=30 loops=13309) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=354895 read=99601 dirtied=613 written=5664 -> Hash (cost=483190.61..483190.61 rows=908697 width=8) (actual time=20010.238..20010.238 rows=911011 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35587kB Buffers: shared hit=334755 read=77372 written=2829 -> Hash Join (cost=135391.26..483190.61 rows=908697 width=8) (actual time=4377.941..19505.422 rows=911011 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=334755 read=77372 written=2829 -> Bitmap Heap Scan on orders (cost=96360.64..418034.94 rows=4543487 width=12) (actual time=2632.166..6770.592 rows=4557440 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=205823 read=60155 written=2829 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..95224.77 rows=4543487 width=0) (actual time=2497.200..2497.200 rows=4561961 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=9392 read=3064 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=1745.396..1745.396 rows=299493 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10530kB Buffers: shared hit=128932 read=17217 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=26.927..1566.844 rows=299493 loops=1) Buffers: shared hit=128932 read=17217 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.040..0.098 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..0.023 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=0.012..0.015 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=31.399..294.135 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=128930 read=17217 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=21.661..21.661 rows=59899 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=8 read=825 -> 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=24245) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72861 read=3 -> 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=24245) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48490 Total runtime: 25749.791 ms (64 rows) COMMIT; COMMIT