BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select n_name, sum(l_extendedprice * (1 - l_discount)) as revenue from customer, orders, lineitem, supplier, nation, region where c_custkey = o_custkey and l_orderkey = o_orderkey and l_suppkey = s_suppkey and c_nationkey = s_nationkey and s_nationkey = n_nationkey and n_regionkey = r_regionkey and r_name = 'EUROPE' and o_orderdate >= date '1993-01-01' and o_orderdate < date '1993-01-01' + interval '1 year' group by n_name order by revenue desc; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1857985.02..1857985.08 rows=25 width=34) (actual time=14873.133..14873.135 rows=5 loops=1) Sort Key: (sum((lineitem.l_extendedprice * (1::double precision - lineitem.l_discount)))) Sort Method: quicksort Memory: 25kB Buffers: shared hit=2140923 read=585501 dirtied=179 written=24387 -> HashAggregate (cost=1857984.19..1857984.44 rows=25 width=34) (actual time=14873.072..14873.073 rows=5 loops=1) Group Key: nation.n_name Buffers: shared hit=2140920 read=585501 dirtied=179 written=24387 -> Hash Join (cost=91937.95..1857255.77 rows=72842 width=34) (actual time=1996.585..14794.160 rows=72750 loops=1) Hash Cond: ((lineitem.l_suppkey = supplier.s_suppkey) AND (customer.c_nationkey = supplier.s_nationkey)) Buffers: shared hit=2140920 read=585501 dirtied=179 written=24387 -> Nested Loop (cost=87258.95..1838190.12 rows=1821097 width=46) (actual time=1923.174..13914.967 rows=1827542 loops=1) Buffers: shared hit=2138738 read=585501 dirtied=179 written=24387 -> Hash Join (cost=87258.38..388510.91 rows=455176 width=38) (actual time=1923.122..5990.164 rows=457006 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=227789 read=178628 dirtied=179 written=8616 -> Bitmap Heap Scan on orders (cost=48216.22..336382.43 rows=2275881 width=8) (actual time=806.287..3706.359 rows=2276798 loops=1) Recheck Cond: ((o_orderdate >= '1993-01-01'::date) AND (o_orderdate < '1994-01-01 00:00:00'::timestamp without time zone)) Heap Blocks: exact=254016 Buffers: shared hit=117718 read=142522 dirtied=179 written=5866 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..47647.24 rows=2275881 width=0) (actual time=721.421..721.421 rows=2283473 loops=1) Index Cond: ((o_orderdate >= '1993-01-01'::date) AND (o_orderdate < '1994-01-01 00:00:00'::timestamp without time zone)) Buffers: shared read=6224 written=398 -> Hash (cost=35292.17..35292.17 rows=300000 width=38) (actual time=1113.818..1113.818 rows=300963 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 25258kB Buffers: shared hit=110071 read=36106 written=2750 -> Nested Loop (cost=905.25..35292.17 rows=300000 width=38) (actual time=18.852..1003.795 rows=300963 loops=1) Buffers: shared hit=110071 read=36106 written=2750 -> Nested Loop (cost=0.14..13.95 rows=5 width=30) (actual time=0.049..0.109 rows=5 loops=1) Join Filter: (nation.n_regionkey = region.r_regionkey) Rows Removed by Join Filter: 20 Buffers: shared hit=3 -> Index Scan using pk_nation on nation (cost=0.14..12.51 rows=25 width=34) (actual time=0.016..0.046 rows=25 loops=1) Buffers: shared hit=2 -> Materialize (cost=0.00..1.07 rows=1 width=4) (actual time=0.001..0.001 rows=1 loops=25) Buffers: shared hit=1 -> Seq Scan on region (cost=0.00..1.06 rows=1 width=4) (actual time=0.011..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=905.11..6455.64 rows=60000 width=8) (actual time=17.233..187.846 rows=60193 loops=5) Recheck Cond: (c_nationkey = nation.n_nationkey) Heap Blocks: exact=145336 Buffers: shared hit=110068 read=36106 written=2750 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=11.363..11.363 rows=60193 loops=5) Index Cond: (c_nationkey = nation.n_nationkey) Buffers: shared hit=6 read=832 written=68 -> Index Scan using lineitem_l_orderkey_idx on lineitem (cost=0.56..3.03 rows=15 width=16) (actual time=0.014..0.016 rows=4 loops=457006) Index Cond: (l_orderkey = orders.o_orderkey) Buffers: shared hit=1910949 read=406873 written=15771 -> Hash (cost=3179.00..3179.00 rows=100000 width=8) (actual time=72.791..72.791 rows=100000 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 4931kB Buffers: shared hit=2179 -> Seq Scan on supplier (cost=0.00..3179.00 rows=100000 width=8) (actual time=0.010..48.247 rows=100000 loops=1) Buffers: shared hit=2179 Planning time: 6.160 ms Execution time: 14876.962 ms (56 rows) COMMIT; COMMIT