BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'VIETNAM' 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 = 'ASIA' and s_nationkey = n2.n_nationkey and o_orderdate between date '1995-01-01' and date '1996-12-31' and p_type = 'SMALL POLISHED NICKEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1713798.41..1713800.24 rows=730 width=38) (actual time=8875.249..8875.249 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=2087592 read=229747 -> HashAggregate (cost=1713750.92..1713763.70 rows=730 width=38) (actual time=8875.155..8875.157 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=2087589 read=229747 -> Hash Join (cost=39448.68..1713269.90 rows=24051 width=38) (actual time=671.487..8839.208 rows=24645 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=2087589 read=229747 -> Nested Loop (cost=39447.11..1712817.38 rows=24051 width=16) (actual time=671.394..8808.706 rows=24645 loops=1) Buffers: shared hit=2087585 read=229747 -> Hash Join (cost=39446.82..1705048.93 rows=24076 width=16) (actual time=671.345..8621.701 rows=24645 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=2015964 read=227299 -> Nested Loop (cost=416.14..1665326.07 rows=120378 width=20) (actual time=11.022..7889.720 rows=122896 loops=1) Buffers: shared hit=1870557 read=226469 -> Nested Loop (cost=415.70..1470799.31 rows=397290 width=16) (actual time=10.501..3469.250 rows=405437 loops=1) Buffers: shared hit=312065 read=161081 -> Bitmap Heap Scan on part (cost=410.98..27997.82 rows=13233 width=4) (actual time=10.393..156.779 rows=13501 loops=1) Recheck Cond: ((p_type)::text = 'SMALL POLISHED NICKEL'::text) Heap Blocks: exact=11485 Buffers: shared hit=4 read=11566 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..407.68 rows=13233 width=0) (actual time=7.963..7.963 rows=13501 loops=1) Index Cond: ((p_type)::text = 'SMALL POLISHED NICKEL'::text) Buffers: shared read=85 -> Bitmap Heap Scan on lineitem (cost=4.72..108.72 rows=31 width=20) (actual time=0.034..0.236 rows=30 loops=13501) Recheck Cond: (l_partkey = part.p_partkey) Heap Blocks: exact=405433 Buffers: shared hit=312061 read=149515 -> Bitmap Index Scan on lineitem_l_partkey_l_quantity_l_shipmode_idx (cost=0.00..4.71 rows=31 width=0) (actual time=0.023..0.023 rows=30 loops=13501) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=40620 read=15523 -> Index Scan using pk_orders on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.010..0.010 rows=0 loops=405437) Index Cond: (o_orderkey = lineitem.l_orderkey) Filter: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Rows Removed by Filter: 1 Buffers: shared hit=1558492 read=65388 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=654.481..654.481 rows=300270 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14653kB Buffers: shared hit=145407 read=830 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=21.513..552.150 rows=300270 loops=1) Buffers: shared hit=145407 read=830 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.036..0.079 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=0.003..0.012 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.014..0.014 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 = 'ASIA'::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=18.025..100.345 rows=60054 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145400 Buffers: shared hit=145405 read=830 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=12.077..12.077 rows=60054 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=5 read=830 -> Index Scan using pk_supplier on supplier (cost=0.29..0.31 rows=1 width=8) (actual time=0.006..0.007 rows=1 loops=24645) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=71621 read=2448 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.039..0.039 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..0.013 rows=25 loops=1) Buffers: shared hit=1 Planning time: 12.372 ms Execution time: 8876.100 ms (72 rows) COMMIT; COMMIT