BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'ALGERIA' 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 = 'STANDARD BURNISHED TIN' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2165625.32..2165627.15 rows=730 width=38) (actual time=27663.166..27663.166 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=712019 read=285670 dirtied=1042 written=127 -> HashAggregate (cost=2165577.83..2165590.60 rows=730 width=38) (actual time=27663.091..27663.092 rows=2 loops=1) Buffers: shared hit=712016 read=285670 dirtied=1042 written=127 -> Nested Loop (cost=496124.92..2165093.47 rows=24218 width=38) (actual time=21645.296..27614.408 rows=24378 loops=1) Buffers: shared hit=712016 read=285670 dirtied=1042 written=127 -> Nested Loop (cost=496124.92..2158186.50 rows=24218 width=16) (actual time=21645.224..27501.257 rows=24378 loops=1) Buffers: shared hit=663260 read=285670 dirtied=1042 written=127 -> Hash Join (cost=496124.92..2151126.28 rows=24245 width=16) (actual time=21645.183..27259.484 rows=24378 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=590002 read=285670 dirtied=1042 written=127 -> Nested Loop (cost=0.00..1652759.44 rows=399893 width=16) (actual time=0.264..4481.331 rows=395436 loops=1) Buffers: shared hit=271970 read=190812 dirtied=788 written=27 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..46184.89 rows=13280 width=4) (actual time=0.218..156.300 rows=13210 loops=1) Index Cond: (p_type = 'STANDARD BURNISHED TIN'::text) Heap Fetches: 13210 Buffers: shared hit=3031 read=8343 written=2 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..120.67 rows=31 width=20) (actual time=0.032..0.316 rows=30 loops=13210) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=268939 read=182469 dirtied=788 written=25 -> Hash (cost=484711.83..484711.83 rows=913047 width=8) (actual time=21644.091..21644.091 rows=911910 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35622kB Buffers: shared hit=318029 read=94858 dirtied=254 written=100 -> Hash Join (cost=135702.19..484711.83 rows=913047 width=8) (actual time=4946.048..21150.353 rows=911910 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=318029 read=94858 dirtied=254 written=100 -> Bitmap Heap Scan on orders (cost=96671.56..419431.10 rows=4565236 width=12) (actual time=3530.783..7550.293 rows=4561773 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=204219 read=62519 dirtied=254 written=15 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..95530.26 rows=4565236 width=0) (actual time=3333.666..3333.666 rows=4575464 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared read=12457 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=1414.860..1414.860 rows=299493 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10530kB Buffers: shared hit=113810 read=32339 written=85 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=22.073..1260.173 rows=299493 loops=1) Buffers: shared hit=113810 read=32339 written=85 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.023..0.086 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..0.017 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..0.010 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=24.994..235.043 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=113808 read=32339 written=85 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=16.632..16.632 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=0.008..0.009 rows=1 loops=24378) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=73258 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.002..0.003 rows=1 loops=24378) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48756 Total runtime: 27678.138 ms (64 rows) COMMIT; COMMIT