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 = 'ECONOMY POLISHED NICKEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1775221.77..1775223.59 rows=729 width=38) (actual time=8832.269..8832.269 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=1744792 read=284878 dirtied=1129 -> HashAggregate (cost=1775174.35..1775187.11 rows=729 width=38) (actual time=8832.213..8832.215 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=1744789 read=284878 dirtied=1129 -> Hash Join (cost=39460.29..1774669.75 rows=25230 width=38) (actual time=899.004..8795.367 rows=24382 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=1744789 read=284878 dirtied=1129 -> Nested Loop (cost=39458.73..1774195.12 rows=25230 width=16) (actual time=898.940..8764.327 rows=24382 loops=1) Buffers: shared hit=1744785 read=284878 dirtied=1129 -> Hash Join (cost=39458.44..1766054.37 rows=25230 width=16) (actual time=898.908..8590.838 rows=24382 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1672051 read=284351 dirtied=1129 -> Nested Loop (cost=427.75..1726298.32 rows=126151 width=20) (actual time=6.539..7629.858 rows=123121 loops=1) Buffers: shared hit=1562004 read=248250 dirtied=1129 -> Nested Loop (cost=427.32..1522276.66 rows=416652 width=16) (actual time=6.172..3792.052 rows=403820 loops=1) Buffers: shared hit=292176 read=182115 dirtied=1036 -> Bitmap Heap Scan on part (cost=422.60..28563.33 rows=13700 width=4) (actual time=6.106..171.833 rows=13440 loops=1) Recheck Cond: ((p_type)::text = 'ECONOMY POLISHED NICKEL'::text) Heap Blocks: exact=11404 Buffers: shared read=11488 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..419.18 rows=13700 width=0) (actual time=4.071..4.071 rows=13440 loops=1) Index Cond: ((p_type)::text = 'ECONOMY POLISHED NICKEL'::text) Buffers: shared read=84 -> Bitmap Heap Scan on lineitem (cost=4.72..108.72 rows=31 width=20) (actual time=0.041..0.259 rows=30 loops=13440) Recheck Cond: (l_partkey = part.p_partkey) Heap Blocks: exact=407027 Buffers: shared hit=292176 read=170627 dirtied=1036 -> Bitmap Index Scan on lineitem_l_partkey_l_quantity_l_shipmode_idx (cost=0.00..4.71 rows=31 width=0) (actual time=0.022..0.022 rows=30 loops=13440) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=38818 read=16958 -> Index Scan using orders_o_orderkey_o_orderdate_idx on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.009..0.009 rows=0 loops=403820) Index Cond: ((o_orderkey = lineitem.l_orderkey) AND (o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=1269828 read=66135 dirtied=93 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=888.770..888.770 rows=299493 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14626kB Buffers: shared hit=110047 read=36101 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=17.082..806.796 rows=299493 loops=1) Buffers: shared hit=110047 read=36101 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.030..0.090 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..0.022 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.013..0.013 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=0.008..0.009 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=15.888..151.153 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145314 Buffers: shared hit=110045 read=36101 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=10.287..10.287 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..0.006 rows=1 loops=24382) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72734 read=527 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.021..0.021 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=0.006..0.010 rows=25 loops=1) Buffers: shared hit=1 Planning time: 6.990 ms Execution time: 8832.957 ms (70 rows) COMMIT; COMMIT