BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'CANADA' 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 = 'AMERICA' and s_nationkey = n2.n_nationkey and o_orderdate between date '1995-01-01' and date '1996-12-31' and p_type = 'PROMO PLATED BRASS' ) as all_nations group by o_year order by o_year; QUERY PLAN ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1777245.44..1777247.27 rows=732 width=38) (actual time=11748.589..11748.589 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=1754006 read=265347 dirtied=918 written=2678 -> HashAggregate (cost=1777197.80..1777210.61 rows=732 width=38) (actual time=11748.511..11748.513 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=1754003 read=265347 dirtied=918 written=2678 -> Hash Join (cost=39460.51..1776692.92 rows=25244 width=38) (actual time=1271.283..11706.067 rows=24269 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=1754003 read=265347 dirtied=918 written=2678 -> Nested Loop (cost=39458.94..1776218.04 rows=25244 width=16) (actual time=1271.214..11667.173 rows=24269 loops=1) Buffers: shared hit=1753999 read=265347 dirtied=918 written=2678 -> Hash Join (cost=39458.65..1768072.74 rows=25244 width=16) (actual time=1271.189..11441.663 rows=24269 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1681049 read=265347 dirtied=918 written=2678 -> Nested Loop (cost=427.97..1728316.29 rows=126221 width=20) (actual time=7.775..10094.946 rows=121998 loops=1) Buffers: shared hit=1570877 read=229582 dirtied=918 written=1220 -> Nested Loop (cost=427.53..1525057.54 rows=415126 width=16) (actual time=7.707..4761.014 rows=401855 loops=1) Buffers: shared hit=279006 read=192445 dirtied=918 written=1038 -> Bitmap Heap Scan on part (cost=426.97..28623.52 rows=13747 width=4) (actual time=7.635..162.156 rows=13406 loops=1) Recheck Cond: ((p_type)::text = 'PROMO PLATED BRASS'::text) Heap Blocks: exact=11436 Buffers: shared hit=4612 read=6894 written=31 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..423.53 rows=13747 width=0) (actual time=5.237..5.237 rows=13406 loops=1) Index Cond: ((p_type)::text = 'PROMO PLATED BRASS'::text) Buffers: shared read=70 written=2 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.56..108.55 rows=31 width=20) (actual time=0.031..0.332 rows=30 loops=13406) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=274394 read=185551 dirtied=918 written=1007 -> Index Scan using orders_o_orderkey_o_orderdate_idx on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.012..0.013 rows=0 loops=401855) Index Cond: ((o_orderkey = lineitem.l_orderkey) AND (o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=1291871 read=37137 written=182 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=1259.644..1259.644 rows=299436 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14624kB Buffers: shared hit=110172 read=35765 written=1458 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=23.553..1162.877 rows=299436 loops=1) Buffers: shared hit=110172 read=35765 written=1458 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.067..0.094 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..0.015 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.026..0.026 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=0.017..0.018 rows=1 loops=1) Filter: (r_name = 'AMERICA'::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=20.620..220.849 rows=59887 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145102 Buffers: shared hit=110170 read=35765 written=1458 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=13.392..13.392 rows=59887 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=7 read=826 written=30 -> Index Scan using pk_supplier on supplier (cost=0.29..0.31 rows=1 width=8) (actual time=0.008..0.008 rows=1 loops=24269) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72950 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.024..0.024 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..0.007 rows=25 loops=1) Buffers: shared hit=1 Planning time: 9.018 ms Execution time: 11749.561 ms (66 rows) COMMIT; COMMIT