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 PLATED NICKEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1691445.96..1691447.79 rows=733 width=38) (actual time=8818.181..8818.181 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=1746256 read=254442 dirtied=2584 written=36 -> HashAggregate (cost=1691398.25..1691411.08 rows=733 width=38) (actual time=8818.127..8818.129 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=1746253 read=254442 dirtied=2584 written=36 -> Hash Join (cost=39434.35..1690921.11 rows=23857 width=38) (actual time=851.023..8782.812 rows=24005 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=1746253 read=254442 dirtied=2584 written=36 -> Nested Loop (cost=39432.79..1690472.23 rows=23857 width=16) (actual time=850.948..8751.277 rows=24005 loops=1) Buffers: shared hit=1746249 read=254442 dirtied=2584 written=36 -> Hash Join (cost=39432.50..1682774.47 rows=23857 width=16) (actual time=850.924..8563.261 rows=24005 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1674102 read=254442 dirtied=2584 written=36 -> Nested Loop (cost=401.81..1643057.90 rows=119285 width=20) (actual time=6.359..7647.869 rows=120755 loops=1) Buffers: shared hit=1541311 read=241085 dirtied=2584 written=36 -> Nested Loop (cost=401.38..1451119.06 rows=391987 width=16) (actual time=6.212..3605.680 rows=397682 loops=1) Buffers: shared hit=267649 read=199456 dirtied=2584 written=27 -> Bitmap Heap Scan on part (cost=400.81..27647.45 rows=12953 width=4) (actual time=6.159..129.291 rows=13247 loops=1) Recheck Cond: ((p_type)::text = 'PROMO PLATED NICKEL'::text) Heap Blocks: exact=11322 Buffers: shared hit=3780 read=7611 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..397.57 rows=12953 width=0) (actual time=4.067..4.067 rows=13247 loops=1) Index Cond: ((p_type)::text = 'PROMO PLATED NICKEL'::text) Buffers: shared read=69 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.56..109.59 rows=31 width=20) (actual time=0.024..0.253 rows=30 loops=13247) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=263869 read=191845 dirtied=2584 written=27 -> Index Scan using orders_o_orderkey_o_orderdate_idx on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.009..0.010 rows=0 loops=397682) Index Cond: ((o_orderkey = lineitem.l_orderkey) AND (o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=1273662 read=41629 written=9 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=842.069..842.069 rows=299493 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14626kB Buffers: shared hit=132791 read=13357 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=18.272..759.947 rows=299493 loops=1) Buffers: shared hit=132791 read=13357 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.038..0.078 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=0.003..0.009 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.015..0.015 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=0.010..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=16.488..141.847 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145314 Buffers: shared hit=132789 read=13357 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=10.676..10.676 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=24005) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72147 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.025..0.025 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=0.004..0.008 rows=25 loops=1) Buffers: shared hit=1 Planning time: 7.439 ms Execution time: 8818.931 ms (66 rows) COMMIT; COMMIT