BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'ETHIOPIA' 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 = 'AFRICA' and s_nationkey = n2.n_nationkey and o_orderdate between date '1995-01-01' and date '1996-12-31' and p_type = 'LARGE ANODIZED STEEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1734141.23..1734143.06 rows=732 width=38) (actual time=10804.676..10804.676 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=1788764 read=216050 dirtied=99 written=9 -> HashAggregate (cost=1734093.59..1734106.40 rows=732 width=38) (actual time=10804.600..10804.602 rows=2 loops=1) Group Key: date_part('year'::text, (orders.o_orderdate)::timestamp without time zone) Buffers: shared hit=1788761 read=216050 dirtied=99 written=9 -> Hash Join (cost=39453.92..1733604.07 rows=24476 width=38) (actual time=1090.682..10762.669 rows=24268 loops=1) Hash Cond: (supplier.s_nationkey = n2.n_nationkey) Buffers: shared hit=1788761 read=216050 dirtied=99 written=9 -> Nested Loop (cost=39452.35..1733143.58 rows=24476 width=16) (actual time=1090.603..10724.263 rows=24268 loops=1) Buffers: shared hit=1788757 read=216050 dirtied=99 written=9 -> Hash Join (cost=39452.06..1725246.08 rows=24476 width=16) (actual time=1090.585..10535.181 rows=24268 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=1715821 read=216050 dirtied=99 written=9 -> Nested Loop (cost=421.38..1685511.70 rows=122381 width=20) (actual time=10.440..9373.010 rows=120977 loops=1) Buffers: shared hit=1570498 read=215225 dirtied=99 written=9 -> Nested Loop (cost=420.94..1488433.88 rows=402498 width=16) (actual time=10.368..5151.899 rows=399090 loops=1) Buffers: shared hit=271609 read=194425 dirtied=99 written=9 -> Bitmap Heap Scan on part (cost=416.22..28194.99 rows=13393 width=4) (actual time=10.217..187.859 rows=13292 loops=1) Recheck Cond: ((p_type)::text = 'LARGE ANODIZED STEEL'::text) Heap Blocks: exact=11377 Buffers: shared hit=1025 read=10435 -> Bitmap Index Scan on part_p_type_p_partkey_idx (cost=0.00..412.88 rows=13393 width=0) (actual time=7.253..7.253 rows=13292 loops=1) Index Cond: ((p_type)::text = 'LARGE ANODIZED STEEL'::text) Buffers: shared read=83 -> Bitmap Heap Scan on lineitem (cost=4.72..108.72 rows=31 width=20) (actual time=0.082..0.362 rows=30 loops=13292) Recheck Cond: (l_partkey = part.p_partkey) Heap Blocks: exact=399441 Buffers: shared hit=270584 read=183990 dirtied=99 written=9 -> Bitmap Index Scan on lineitem_l_partkey_l_quantity_l_shipmode_idx (cost=0.00..4.71 rows=31 width=0) (actual time=0.066..0.066 rows=30 loops=13292) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=39077 read=16056 written=1 -> 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=399090) Index Cond: ((o_orderkey = lineitem.l_orderkey) AND (o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=1298889 read=20800 -> Hash (cost=35280.69..35280.69 rows=300000 width=4) (actual time=1076.506..1076.506 rows=299493 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 14626kB Buffers: shared hit=145323 read=825 -> Nested Loop (cost=906.18..35280.69 rows=300000 width=4) (actual time=31.381..936.727 rows=299493 loops=1) Buffers: shared hit=145323 read=825 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.060..0.095 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=0.005..0.014 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.027..0.027 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=0.017..0.019 rows=1 loops=1) Filter: (r_name = 'AFRICA'::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=27.706..169.595 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Heap Blocks: exact=145314 Buffers: shared hit=145321 read=825 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=18.652..18.652 rows=59899 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=7 read=825 -> 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=24268) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=72936 -> Hash (cost=1.25..1.25 rows=25 width=30) (actual time=0.033..0.033 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..0.009 rows=25 loops=1) Buffers: shared hit=1 Planning time: 11.893 ms Execution time: 10805.694 ms (70 rows) COMMIT; COMMIT