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 PLATED COPPER' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2146340.63..2146342.45 rows=730 width=38) (actual time=11520.743..11520.743 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=809479 read=189458 -> HashAggregate (cost=2146293.13..2146305.91 rows=730 width=38) (actual time=11520.660..11520.661 rows=2 loops=1) Buffers: shared hit=809476 read=189458 -> Nested Loop (cost=494909.45..2145816.03 rows=23855 width=38) (actual time=7348.798..11490.632 rows=24239 loops=1) Buffers: shared hit=809476 read=189458 -> Nested Loop (cost=494909.45..2139012.59 rows=23855 width=16) (actual time=7348.738..11430.993 rows=24239 loops=1) Buffers: shared hit=760998 read=189458 -> Hash Join (cost=494909.45..2132058.35 rows=23881 width=16) (actual time=7348.637..11229.332 rows=24239 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=690604 read=187010 -> Nested Loop (cost=0.00..1634940.61 rows=393896 width=16) (actual time=1.248..3198.667 rows=398771 loops=1) Buffers: shared hit=310639 read=154817 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..45702.09 rows=13120 width=4) (actual time=1.062..139.401 rows=13291 loops=1) Index Cond: (p_type = 'MEDIUM PLATED COPPER'::text) Heap Fetches: 13291 Buffers: shared hit=1 read=11438 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..120.82 rows=31 width=20) (actual time=0.024..0.222 rows=30 loops=13291) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=310638 read=143379 -> Hash (cost=483530.43..483530.43 rows=910322 width=8) (actual time=7346.378..7346.378 rows=913948 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35702kB Buffers: shared hit=379962 read=32193 -> Hash Join (cost=135562.52..483530.43 rows=910322 width=8) (actual time=1659.491..7075.504 rows=913948 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=379962 read=32193 -> Bitmap Heap Scan on orders (cost=96531.90..418328.05 rows=4551610 width=12) (actual time=1032.518..3054.109 rows=4561961 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=234618 read=31360 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..95394.00 rows=4551610 width=0) (actual time=962.466..962.466 rows=4561961 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared read=12456 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=626.652..626.652 rows=300963 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10581kB Buffers: shared hit=145344 read=833 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=31.864..555.690 rows=300963 loops=1) Buffers: shared hit=145344 read=833 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.032..0.084 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=0.015..0.015 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=0.010..0.011 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=19.260..101.112 rows=60193 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=145342 read=833 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=13.453..13.453 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=0.007..0.007 rows=1 loops=24239) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=70394 read=2448 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.001..0.001 rows=1 loops=24239) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48478 Total runtime: 11529.820 ms (64 rows) COMMIT; COMMIT