BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'UNITED KINGDOM' 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 = 'EUROPE' and s_nationkey = n2.n_nationkey and o_orderdate between date '1995-01-01' and date '1996-12-31' and p_type = 'STANDARD PLATED COPPER' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2168027.09..2168028.92 rows=733 width=38) (actual time=38380.097..38380.097 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=728175 read=279524 dirtied=2481 written=40911 -> HashAggregate (cost=2167979.38..2167992.21 rows=733 width=38) (actual time=38380.021..38380.022 rows=2 loops=1) Buffers: shared hit=728172 read=279524 dirtied=2481 written=40911 -> Nested Loop (cost=502555.99..2167491.26 rows=24406 width=38) (actual time=26099.278..38299.058 rows=24471 loops=1) Buffers: shared hit=728172 read=279524 dirtied=2481 written=40911 -> Nested Loop (cost=502555.99..2160530.67 rows=24406 width=16) (actual time=26099.201..37975.964 rows=24471 loops=1) Buffers: shared hit=679230 read=279524 dirtied=2481 written=40911 -> Hash Join (cost=502555.99..2153423.59 rows=24406 width=16) (actual time=26099.144..37449.224 rows=24471 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=605675 read=279524 dirtied=2481 written=40911 -> Nested Loop (cost=0.00..1648618.16 rows=401075 width=16) (actual time=0.509..9973.040 rows=399080 loops=1) Buffers: shared hit=223765 read=246035 dirtied=2481 written=40911 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..46027.51 rows=13227 width=4) (actual time=0.399..322.586 rows=13284 loops=1) Index Cond: (p_type = 'STANDARD PLATED COPPER'::text) Heap Fetches: 13284 Buffers: shared hit=2208 read=9277 written=1899 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..120.85 rows=31 width=20) (actual time=0.065..0.709 rows=30 loops=13284) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=221557 read=236758 dirtied=2481 written=39012 -> Hash (cost=491020.67..491020.67 rows=922826 width=8) (actual time=26094.762..26094.762 rows=913882 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35699kB Buffers: shared hit=381907 read=33489 -> Hash Join (cost=139223.45..491020.67 rows=922826 width=8) (actual time=6395.738..25405.296 rows=913882 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=381907 read=33489 -> Bitmap Heap Scan on orders (cost=100192.83..425458.80 rows=4614131 width=12) (actual time=4234.771..11328.336 rows=4561778 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=237933 read=31286 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..99039.30 rows=4614131 width=0) (actual time=4106.032..4106.032 rows=4607485 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared read=13165 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=2160.700..2160.700 rows=300963 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10581kB Buffers: shared hit=143974 read=2203 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=48.808..1963.947 rows=300963 loops=1) Buffers: shared hit=143974 read=2203 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.045..0.126 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=0.006..0.024 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.022..0.022 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=0.019..0.020 rows=1 loops=1) Filter: (r_name = 'EUROPE'::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=41.665..372.058 rows=60193 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=143972 read=2203 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=30.745..30.745 rows=60193 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=7 read=832 -> Index Scan using pk_supplier on supplier (cost=0.00..0.28 rows=1 width=8) (actual time=0.019..0.019 rows=1 loops=24471) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=73555 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.009..0.010 rows=1 loops=24471) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48942 Total runtime: 38394.194 ms (64 rows) COMMIT; COMMIT