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 = 'MEDIUM POLISHED TIN' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2176059.74..2176061.57 rows=729 width=38) (actual time=30984.376..30984.377 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=713802 read=294759 dirtied=3703 written=113 -> HashAggregate (cost=2176012.32..2176025.08 rows=729 width=38) (actual time=30984.296..30984.298 rows=2 loops=1) Buffers: shared hit=713799 read=294759 dirtied=3703 written=113 -> Nested Loop (cost=503245.15..2175535.88 rows=23822 width=38) (actual time=23679.797..30918.992 rows=24275 loops=1) Buffers: shared hit=713799 read=294759 dirtied=3703 written=113 -> Nested Loop (cost=503245.15..2168741.85 rows=23822 width=16) (actual time=23679.711..30752.947 rows=24275 loops=1) Buffers: shared hit=665249 read=294759 dirtied=3703 written=113 -> Hash Join (cost=503245.15..2161795.82 rows=23853 width=16) (actual time=23679.652..30401.094 rows=24275 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=592292 read=294759 dirtied=3703 written=113 -> Nested Loop (cost=0.00..1656341.47 rows=394135 width=16) (actual time=0.516..5569.872 rows=398777 loops=1) Buffers: shared hit=295565 read=175024 dirtied=3703 written=13 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..45182.90 rows=12947 width=4) (actual time=0.432..243.771 rows=13296 loops=1) Index Cond: (p_type = 'MEDIUM POLISHED TIN'::text) Heap Fetches: 13296 Buffers: shared hit=1 read=11466 written=2 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..124.12 rows=32 width=20) (actual time=0.042..0.386 rows=30 loops=13296) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=295564 read=163558 dirtied=3703 written=11 -> Hash (cost=491727.65..491727.65 rows=921400 width=8) (actual time=23677.703..23677.703 rows=913899 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35700kB Buffers: shared hit=296724 read=119735 written=100 -> Hash Join (cost=139066.38..491727.65 rows=921400 width=8) (actual time=5088.167..23005.791 rows=913899 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=296724 read=119735 written=100 -> Bitmap Heap Scan on orders (cost=100035.76..426206.77 rows=4607001 width=12) (actual time=3268.829..8666.042 rows=4561762 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=186654 read=83628 written=100 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..98884.01 rows=4607001 width=0) (actual time=3079.017..3079.017 rows=4625776 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=78 read=13138 written=95 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=1819.009..1819.009 rows=300963 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10581kB Buffers: shared hit=110070 read=36107 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=33.210..1646.817 rows=300963 loops=1) Buffers: shared hit=110070 read=36107 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.040..0.101 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=0.007..0.023 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.017..0.017 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=0.014..0.016 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=32.319..310.520 rows=60193 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=110068 read=36107 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=22.740..22.740 rows=60193 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=6 read=833 -> Index Scan using pk_supplier on supplier (cost=0.00..0.28 rows=1 width=8) (actual time=0.012..0.012 rows=1 loops=24275) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72957 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.004..0.004 rows=1 loops=24275) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48550 Total runtime: 30994.447 ms (64 rows) COMMIT; COMMIT