BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'ALGERIA' 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=2149630.42..2149632.25 rows=732 width=38) (actual time=66730.022..66730.023 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=748798 read=253818 dirtied=2452 written=96 -> HashAggregate (cost=2149582.78..2149595.59 rows=732 width=38) (actual time=66729.952..66729.955 rows=2 loops=1) Buffers: shared hit=748795 read=253818 dirtied=2452 written=96 -> Nested Loop (cost=501830.26..2149101.74 rows=24052 width=38) (actual time=37412.843..66599.888 rows=24120 loops=1) Buffers: shared hit=748795 read=253818 dirtied=2452 written=96 -> Nested Loop (cost=501830.26..2142242.11 rows=24052 width=16) (actual time=37412.747..65014.260 rows=24120 loops=1) Buffers: shared hit=700555 read=253818 dirtied=2452 written=96 -> Hash Join (cost=501830.26..2135236.95 rows=24056 width=16) (actual time=37412.694..63368.654 rows=24120 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=628063 read=253818 dirtied=2452 written=96 -> Nested Loop (cost=0.00..1631187.02 rows=395824 width=16) (actual time=0.551..24420.965 rows=397044 loops=1) Buffers: shared hit=233719 read=233061 dirtied=2199 written=96 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..45544.52 rows=13067 width=4) (actual time=0.386..655.362 rows=13240 loops=1) Index Cond: (p_type = 'LARGE PLATED TIN'::text) Heap Fetches: 13240 Buffers: shared hit=5145 read=6244 written=4 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..121.04 rows=31 width=20) (actual time=0.196..1.774 rows=30 loops=13240) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=228574 read=226817 dirtied=2199 written=92 -> Hash (cost=490320.96..490320.96 rows=920744 width=8) (actual time=37411.028..37411.028 rows=911892 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35621kB Buffers: shared hit=394341 read=20757 dirtied=253 -> Hash Join (cost=138992.75..490320.96 rows=920744 width=8) (actual time=10322.143..36728.080 rows=911892 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=394341 read=20757 dirtied=253 -> Bitmap Heap Scan on orders (cost=99962.13..424818.94 rows=4603721 width=12) (actual time=5002.086..17634.496 rows=4561673 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=249018 read=19931 dirtied=253 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..98811.20 rows=4603721 width=0) (actual time=4882.295..4882.295 rows=4602796 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=2 read=13146 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=5319.717..5319.717 rows=299493 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10530kB Buffers: shared hit=145323 read=826 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=60.820..5116.243 rows=299493 loops=1) Buffers: shared hit=145323 read=826 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.239..0.301 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..0.020 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.213..0.213 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=0.206..0.208 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=49.684..1002.831 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=145321 read=826 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=39.512..39.512 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=0.064..0.064 rows=1 loops=24120) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72492 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.060..0.060 rows=1 loops=24120) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48240 Total runtime: 66747.342 ms (64 rows) COMMIT; COMMIT