BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'CANADA' 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 = 'AMERICA' and s_nationkey = n2.n_nationkey and o_orderdate between date '1995-01-01' and date '1996-12-31' and p_type = 'LARGE PLATED COPPER' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2134636.16..2134637.98 rows=728 width=38) (actual time=42800.950..42800.951 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=760223 read=231896 dirtied=647 written=267 -> HashAggregate (cost=2134588.81..2134601.55 rows=728 width=38) (actual time=42800.882..42800.884 rows=2 loops=1) Buffers: shared hit=760220 read=231896 dirtied=647 written=267 -> Nested Loop (cost=495073.32..2134116.03 rows=23639 width=38) (actual time=28133.920..42710.965 rows=24030 loops=1) Buffers: shared hit=760220 read=231896 dirtied=647 written=267 -> Nested Loop (cost=495073.32..2127374.19 rows=23639 width=16) (actual time=28133.859..42399.607 rows=24030 loops=1) Buffers: shared hit=712160 read=231896 dirtied=647 written=267 -> Hash Join (cost=495073.32..2120488.11 rows=23647 width=16) (actual time=28133.818..41643.711 rows=24030 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=639923 read=231896 dirtied=647 written=267 -> Nested Loop (cost=0.00..1623221.89 rows=391286 width=16) (actual time=5.962..12021.282 rows=392919 loops=1) Buffers: shared hit=271941 read=187453 dirtied=395 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..45363.84 rows=13007 width=4) (actual time=1.860..323.678 rows=13106 loops=1) Index Cond: (p_type = 'LARGE PLATED COPPER'::text) Heap Fetches: 13106 Buffers: shared hit=5196 read=6064 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..121.00 rows=31 width=20) (actual time=0.099..0.875 rows=30 loops=13106) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=266745 read=181389 dirtied=395 -> Hash (cost=483707.88..483707.88 rows=909235 width=8) (actual time=28125.697..28125.697 rows=911247 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35596kB Buffers: shared hit=367979 read=44443 dirtied=252 written=267 -> Hash Join (cost=135346.79..483707.88 rows=909235 width=8) (actual time=7552.927..26456.732 rows=911247 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=367979 read=44443 dirtied=252 written=267 -> Bitmap Heap Scan on orders (cost=96316.17..418536.76 rows=4546173 width=12) (actual time=4057.504..10396.464 rows=4561956 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=244539 read=21945 dirtied=252 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..95179.63 rows=4546173 width=0) (actual time=3923.839..3923.839 rows=4570988 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=1 read=12455 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=3495.095..3495.095 rows=299436 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10528kB Buffers: shared hit=123440 read=22498 written=267 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=50.295..3270.023 rows=299436 loops=1) Buffers: shared hit=123440 read=22498 written=267 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.054..0.123 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=0.012..0.029 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.024..0.024 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=0.020..0.022 rows=1 loops=1) Filter: (r_name = 'AMERICA'::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=42.084..632.271 rows=59887 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=123438 read=22498 written=267 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=31.188..31.188 rows=59887 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=8 read=826 -> Index Scan using pk_supplier on supplier (cost=0.00..0.28 rows=1 width=8) (actual time=0.028..0.029 rows=1 loops=24030) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72237 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.008..0.009 rows=1 loops=24030) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48060 Total runtime: 42819.486 ms (64 rows) COMMIT; COMMIT