BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'KENYA' 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 = 'LARGE PLATED TIN' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2144285.16..2144286.99 rows=729 width=38) (actual time=28535.845..28535.846 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=709886 read=288118 dirtied=373 -> HashAggregate (cost=2144237.74..2144250.50 rows=729 width=38) (actual time=28535.774..28535.774 rows=2 loops=1) Buffers: shared hit=709883 read=288118 dirtied=373 -> Nested Loop (cost=495764.03..2143761.36 rows=23819 width=38) (actual time=21228.266..28474.852 rows=24094 loops=1) Buffers: shared hit=709883 read=288118 dirtied=373 -> Nested Loop (cost=495764.03..2136968.18 rows=23819 width=16) (actual time=21228.185..28312.831 rows=24094 loops=1) Buffers: shared hit=661695 read=288118 dirtied=373 -> Hash Join (cost=495764.03..2130022.99 rows=23850 width=16) (actual time=21228.136..27994.132 rows=24094 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=589280 read=288118 dirtied=373 -> Nested Loop (cost=0.00..1632050.06 rows=394081 width=16) (actual time=0.428..5500.185 rows=396959 loops=1) Buffers: shared hit=270924 read=193584 dirtied=373 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..45605.35 rows=13087 width=4) (actual time=0.342..224.112 rows=13240 loops=1) Index Cond: (p_type = 'LARGE PLATED TIN'::text) Heap Fetches: 13240 Buffers: shared hit=364 read=11025 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..120.91 rows=31 width=20) (actual time=0.039..0.384 rows=30 loops=13240) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=270560 read=182559 dirtied=373 -> Hash (cost=484371.31..484371.31 rows=911418 width=8) (actual time=21226.823..21226.823 rows=911910 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35622kB Buffers: shared hit=318353 read=94534 -> Hash Join (cost=135530.69..484371.31 rows=911418 width=8) (actual time=5037.384..20475.780 rows=911910 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=318353 read=94534 -> Bitmap Heap Scan on orders (cost=96500.07..419137.42 rows=4557090 width=12) (actual time=3264.090..7383.257 rows=4561773 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=208305 read=58433 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..95360.80 rows=4557090 width=0) (actual time=3129.630..3129.630 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=1773.019..1773.019 rows=299493 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10530kB Buffers: shared hit=110048 read=36101 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=33.569..1590.631 rows=299493 loops=1) Buffers: shared hit=110048 read=36101 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.051..0.113 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=0.005..0.018 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.035..0.035 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=0.031..0.033 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=32.810..298.540 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=110046 read=36101 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=22.753..22.753 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=0.011..0.011 rows=1 loops=24094) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72415 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.004..0.004 rows=1 loops=24094) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48188 Total runtime: 28555.206 ms (64 rows) COMMIT; COMMIT