BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'GERMANY' 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 = 'ECONOMY PLATED COPPER' ) as all_nations group by o_year order by o_year; QUERY PLAN ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1732010.33..1732012.16 rows=732 width=38) (actual time=10272.803..10272.803 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=1705807 read=296993 dirtied=1472 written=154 -> HashAggregate (cost=1731962.69..1731975.50 rows=732 width=38) (actual time=10272.734..10272.736 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=1705804 read=296993 dirtied=1472 written=154 -> Hash Join (cost=39445.10..1731470.97 rows=24586 width=38) (actual time=1201.138..10232.728 rows=24474 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=1705804 read=296993 dirtied=1472 written=154 -> Nested Loop (cost=39443.53..1731008.42 rows=24586 width=16) (actual time=1201.070..10196.781 rows=24474 loops=1) Buffers: shared hit=1705800 read=296993 dirtied=1472 written=154 -> Hash Join (cost=39443.24..1723075.47 rows=24586 width=16) (actual time=1201.048..10009.396 rows=24474 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1632248 read=296993 dirtied=1472 written=154 -> Nested Loop (cost=412.56..1683337.93 rows=122930 width=20) (actual time=7.980..8733.417 rows=121371 loops=1) Buffers: shared hit=1522165 read=260900 dirtied=1472 written=105 -> Nested Loop (cost=412.12..1485364.29 rows=404303 width=16) (actual time=7.861..4351.963 rows=397899 loops=1) Buffers: shared hit=261388 read=205215 dirtied=1443 written=75 -> Bitmap Heap Scan on part (cost=411.56..28088.03 rows=13307 width=4) (actual time=7.778..175.370 rows=13246 loops=1) Recheck Cond: ((p_type)::text = 'ECONOMY PLATED COPPER'::text) Heap Blocks: exact=11381 Buffers: shared hit=1537 read=9927 written=7 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..408.23 rows=13307 width=0) (actual time=5.370..5.370 rows=13246 loops=1) Index Cond: ((p_type)::text = 'ECONOMY PLATED COPPER'::text) Buffers: shared read=83 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.56..109.20 rows=31 width=20) (actual time=0.028..0.305 rows=30 loops=13246) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=259851 read=195288 dirtied=1443 written=68 -> Index Scan using orders_o_orderkey_o_orderdate_idx on orders (cost=0.43..0.48 rows=1 width=12) (actual time=0.010..0.010 rows=0 loops=397899) Index Cond: ((o_orderkey = lineitem.l_orderkey) AND (o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=1260777 read=55685 dirtied=29 written=30 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=1189.402..1189.402 rows=300963 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14677kB Buffers: shared hit=110083 read=36093 written=49 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=24.012..1092.060 rows=300963 loops=1) Buffers: shared hit=110083 read=36093 written=49 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.063..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=0.006..0.016 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.025..0.025 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=0.019..0.019 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=19.959..206.806 rows=60193 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145336 Buffers: shared hit=110081 read=36093 written=49 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=13.167..13.167 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..0.007 rows=1 loops=24474) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=73552 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.025..0.025 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=0.005..0.009 rows=25 loops=1) Buffers: shared hit=1 Planning time: 8.495 ms Execution time: 10273.720 ms (66 rows) COMMIT; COMMIT