BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'MOROCCO' 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 PLATED COPPER' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2185744.67..2185746.50 rows=732 width=38) (actual time=62865.591..62865.591 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=800379 read=202797 dirtied=2658 written=215 -> HashAggregate (cost=2185697.03..2185709.84 rows=732 width=38) (actual time=62865.519..62865.522 rows=2 loops=1) Buffers: shared hit=800376 read=202797 dirtied=2658 written=215 -> Nested Loop (cost=503210.87..2185202.99 rows=24702 width=38) (actual time=35507.491..62741.213 rows=24189 loops=1) Buffers: shared hit=800376 read=202797 dirtied=2658 written=215 -> Nested Loop (cost=503210.87..2178157.98 rows=24702 width=16) (actual time=35507.438..61048.379 rows=24189 loops=1) Buffers: shared hit=751998 read=202797 dirtied=2658 written=215 -> Hash Join (cost=503210.87..2170963.56 rows=24706 width=16) (actual time=35507.399..59287.992 rows=24189 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=679288 read=202797 dirtied=2658 written=215 -> Nested Loop (cost=0.00..1665473.04 rows=406517 width=16) (actual time=1.686..22050.253 rows=395629 loops=1) Buffers: shared hit=278503 read=187679 dirtied=2570 written=17 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..46485.98 rows=13380 width=4) (actual time=1.632..672.953 rows=13163 loops=1) Index Cond: (p_type = 'SMALL PLATED COPPER'::text) Heap Fetches: 13163 Buffers: shared hit=5230 read=6174 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..120.69 rows=31 width=20) (actual time=0.186..1.604 rows=30 loops=13163) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=273273 read=181505 dirtied=2570 written=17 -> Hash (cost=491667.42..491667.42 rows=923476 width=8) (actual time=35504.710..35504.710 rows=912000 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35625kB Buffers: shared hit=400782 read=15118 dirtied=88 written=198 -> Hash Join (cost=139296.77..491667.42 rows=923476 width=8) (actual time=8601.224..34526.629 rows=912000 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=400782 read=15118 dirtied=88 written=198 -> Bitmap Heap Scan on orders (cost=100266.15..426086.86 rows=4617381 width=12) (actual time=4878.697..16808.959 rows=4561702 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=255149 read=14602 dirtied=88 written=152 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..99111.80 rows=4617381 width=0) (actual time=4736.273..4736.273 rows=4616605 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=741 read=12450 written=152 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=3722.169..3722.169 rows=299493 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10530kB Buffers: shared hit=145633 read=516 written=46 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=35.413..3516.496 rows=299493 loops=1) Buffers: shared hit=145633 read=516 written=46 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.341..0.419 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=0.308..0.324 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=0.014..0.016 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=41.565..682.390 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=145631 read=516 written=46 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=30.911..30.911 rows=59899 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=398 read=435 written=39 -> Index Scan using pk_supplier on supplier (cost=0.00..0.28 rows=1 width=8) (actual time=0.069..0.069 rows=1 loops=24189) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72710 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.064..0.065 rows=1 loops=24189) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48378 Total runtime: 62881.887 ms (64 rows) COMMIT; COMMIT