BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'ROMANIA' 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 = 'MEDIUM BURNISHED TIN' ) as all_nations group by o_year order by o_year; QUERY PLAN ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1726782.49..1726784.31 rows=727 width=38) (actual time=8572.379..8572.380 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=1685281 read=317781 dirtied=3605 written=392 -> HashAggregate (cost=1726735.21..1726747.93 rows=727 width=38) (actual time=8572.328..8572.329 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=1685278 read=317781 dirtied=3605 written=392 -> Hash Join (cost=39434.10..1726260.33 rows=23744 width=38) (actual time=929.383..8538.720 rows=23915 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=1685278 read=317781 dirtied=3605 written=392 -> Nested Loop (cost=39432.54..1725813.57 rows=23744 width=16) (actual time=929.312..8509.839 rows=23915 loops=1) Buffers: shared hit=1685274 read=317781 dirtied=3605 written=392 -> Hash Join (cost=39432.24..1718152.30 rows=23744 width=16) (actual time=929.278..8337.902 rows=23915 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1613393 read=317781 dirtied=3605 written=392 -> Nested Loop (cost=401.56..1678438.96 rows=118722 width=20) (actual time=7.184..7348.466 rows=120600 loops=1) Buffers: shared hit=1503323 read=281675 dirtied=3605 written=392 -> Nested Loop (cost=401.12..1486032.75 rows=392931 width=16) (actual time=7.134..3678.009 rows=398303 loops=1) Buffers: shared hit=263024 read=205082 dirtied=3537 written=372 -> Bitmap Heap Scan on part (cost=400.56..27605.81 rows=12920 width=4) (actual time=7.076..162.577 rows=13268 loops=1) Recheck Cond: ((p_type)::text = 'MEDIUM BURNISHED TIN'::text) Heap Blocks: exact=11330 Buffers: shared hit=1 read=11412 written=17 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..397.33 rows=12920 width=0) (actual time=4.728..4.728 rows=13268 loops=1) Index Cond: ((p_type)::text = 'MEDIUM BURNISHED TIN'::text) Buffers: shared read=83 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.56..112.56 rows=32 width=20) (actual time=0.024..0.255 rows=30 loops=13268) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=263023 read=193670 dirtied=3537 written=355 -> Index Scan using orders_o_orderkey_o_orderdate_idx on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.009..0.009 rows=0 loops=398303) Index Cond: ((o_orderkey = lineitem.l_orderkey) AND (o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=1240299 read=76593 dirtied=68 written=20 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=918.568..918.568 rows=300963 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14677kB Buffers: shared hit=110070 read=36106 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=20.409..835.082 rows=300963 loops=1) Buffers: shared hit=110070 read=36106 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.049..0.102 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..0.019 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..0.008 rows=1 loops=1) Filter: (r_name = 'EUROPE'::bpchar) Rows Removed by Filter: 4 Buffers: shared hit=1 -> Bitmap Heap Scan on customer (cost=905.11..6455.64 rows=60000 width=8) (actual time=16.286..156.613 rows=60193 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145336 Buffers: shared hit=110068 read=36106 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=10.517..10.517 rows=60193 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=6 read=832 -> Index Scan using pk_supplier on supplier (cost=0.29..0.31 rows=1 width=8) (actual time=0.006..0.006 rows=1 loops=23915) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=71881 -> 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..0.010 rows=25 loops=1) Buffers: shared hit=1 Planning time: 11.196 ms Execution time: 8573.158 ms (66 rows) COMMIT; COMMIT