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 = 'ECONOMY BRUSHED STEEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1721151.96..1721153.78 rows=730 width=38) (actual time=10388.497..10388.498 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=2046261 read=252484 dirtied=475 written=31 -> HashAggregate (cost=1721104.47..1721117.24 rows=730 width=38) (actual time=10388.439..10388.440 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=2046258 read=252484 dirtied=475 written=31 -> Hash Join (cost=39444.63..1720621.99 rows=24124 width=38) (actual time=1111.334..10350.554 rows=24181 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=2046258 read=252484 dirtied=475 written=31 -> Nested Loop (cost=39443.07..1720168.10 rows=24124 width=16) (actual time=1111.272..10318.067 rows=24181 loops=1) Buffers: shared hit=2046254 read=252484 dirtied=475 written=31 -> Hash Join (cost=39442.78..1712376.10 rows=24149 width=16) (actual time=1111.257..10131.818 rows=24181 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1973562 read=252484 dirtied=475 written=31 -> Nested Loop (cost=412.09..1672651.13 rows=120746 width=20) (actual time=7.427..8958.275 rows=122248 loops=1) Buffers: shared hit=1863515 read=216383 dirtied=475 -> Nested Loop (cost=411.66..1477527.30 rows=398505 width=16) (actual time=7.296..3822.115 rows=401953 loops=1) Buffers: shared hit=287188 read=182698 dirtied=408 -> Bitmap Heap Scan on part (cost=411.09..28014.26 rows=13247 width=4) (actual time=7.205..186.279 rows=13411 loops=1) Recheck Cond: ((p_type)::text = 'ECONOMY BRUSHED STEEL'::text) Heap Blocks: exact=11429 Buffers: shared hit=1 read=11512 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..407.78 rows=13247 width=0) (actual time=4.966..4.966 rows=13411 loops=1) Index Cond: ((p_type)::text = 'ECONOMY BRUSHED STEEL'::text) Buffers: shared read=84 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.56..109.11 rows=31 width=20) (actual time=0.027..0.261 rows=30 loops=13411) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=287187 read=171186 dirtied=408 -> Index Scan using pk_orders on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.012..0.012 rows=0 loops=401953) Index Cond: (o_orderkey = lineitem.l_orderkey) Filter: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Rows Removed by Filter: 1 Buffers: shared hit=1576327 read=33685 dirtied=67 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=1099.579..1099.579 rows=299493 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14626kB Buffers: shared hit=110047 read=36101 written=31 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=20.633..1006.909 rows=299493 loops=1) Buffers: shared hit=110047 read=36101 written=31 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.046..0.077 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=0.008..0.018 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.017..0.017 rows=1 loops=1) Buckets: 1024 Batches: 1 Memory Usage: 9kB Buffers: shared hit=1 -> Seq Scan on region (cost=0.00..1.06 rows=1 width=4) (actual time=0.009..0.011 rows=1 loops=1) Filter: (r_name = 'AFRICA'::bpchar) Rows Removed by Filter: 4 Buffers: shared hit=1 -> Bitmap Heap Scan on customer (cost=905.11..6455.64 rows=60000 width=8) (actual time=18.279..190.446 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145314 Buffers: shared hit=110045 read=36101 written=31 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=11.938..11.938 rows=59899 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=7 read=825 -> Index Scan using pk_supplier on supplier (cost=0.29..0.31 rows=1 width=8) (actual time=0.006..0.007 rows=1 loops=24181) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72692 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.026..0.026 rows=25 loops=1) Buckets: 1024 Batches: 1 Memory Usage: 10kB Buffers: shared hit=1 -> Seq Scan on nation n2 (cost=0.00..1.25 rows=25 width=30) (actual time=0.005..0.007 rows=25 loops=1) Buffers: shared hit=1 Planning time: 8.013 ms Execution time: 10389.413 ms (68 rows) COMMIT; COMMIT