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 '1996-01-01' and o_orderdate < date '1996-01-01' + interval '1 year' group by n_name order by revenue desc; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2452296.79..2452296.85 rows=25 width=34) (actual time=73888.283..73888.284 rows=5 loops=1) Sort Key: (sum((lineitem.l_extendedprice * (1::double precision - lineitem.l_discount)))) Sort Method: quicksort Memory: 25kB Buffers: shared hit=809563 read=681211 written=38 -> HashAggregate (cost=2452295.96..2452296.21 rows=25 width=34) (actual time=73888.120..73888.123 rows=5 loops=1) Buffers: shared hit=809560 read=681211 written=38 -> Hash Join (cost=404476.91..2451555.44 rows=74052 width=34) (actual time=13956.659..73744.671 rows=73043 loops=1) Hash Cond: ((lineitem.l_suppkey = supplier.s_suppkey) AND (customer.c_nationkey = supplier.s_nationkey)) Buffers: shared hit=809560 read=681211 written=38 -> Hash Join (cost=399797.91..2409069.82 rows=1853305 width=46) (actual time=13827.400..70025.380 rows=1828600 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=807378 read=681211 written=38 -> Seq Scan on lineitem (cost=0.00..1686913.24 rows=60765124 width=16) (actual time=0.050..15712.217 rows=59985538 loops=1) Buffers: shared hit=478527 read=600735 -> Hash (cost=394004.94..394004.94 rows=463437 width=38) (actual time=13826.625..13826.625 rows=457410 loops=1) Buckets: 65536 Batches: 1 Memory Usage: 32162kB Buffers: shared hit=328851 read=80476 written=38 -> Hash Join (cost=89363.36..394004.94 rows=463437 width=38) (actual time=3495.919..12815.238 rows=457410 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=328851 read=80476 written=38 -> Bitmap Heap Scan on orders (cost=50321.14..341638.91 rows=2317185 width=8) (actual time=1833.280..4963.770 rows=2281952 loops=1) Recheck Cond: ((o_orderdate >= '1996-01-01'::date) AND (o_orderdate < '1997-01-01 00:00:00'::timestamp without time zone)) Buffers: shared hit=218777 read=44372 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..49741.84 rows=2317185 width=0) (actual time=1717.874..1717.874 rows=2311554 loops=1) Index Cond: ((o_orderdate >= '1996-01-01'::date) AND (o_orderdate < '1997-01-01 00:00:00'::timestamp without time zone)) Buffers: shared read=6606 -> Hash (cost=35292.22..35292.22 rows=300000 width=38) (actual time=1662.282..1662.282 rows=300963 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 21162kB Buffers: shared hit=110074 read=36104 written=38 -> Nested Loop (cost=905.09..35292.22 rows=300000 width=38) (actual time=34.567..1465.907 rows=300963 loops=1) Buffers: shared hit=110074 read=36104 written=38 -> Nested Loop (cost=0.00..14.07 rows=5 width=30) (actual time=0.063..0.166 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=0.00..12.63 rows=25 width=34) (actual time=0.009..0.059 rows=25 loops=1) Buffers: shared hit=2 -> Materialize (cost=0.00..1.07 rows=1 width=4) (actual time=0.002..0.002 rows=1 loops=25) Buffers: shared hit=1 -> Seq Scan on region (cost=0.00..1.06 rows=1 width=4) (actual time=0.027..0.028 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=30.510..270.113 rows=60193 loops=5) Recheck Cond: (c_nationkey = nation.n_nationkey) Buffers: shared hit=110071 read=36104 written=38 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=20.422..20.422 rows=60193 loops=5) Index Cond: (c_nationkey = nation.n_nationkey) Buffers: shared hit=6 read=833 written=10 -> Hash (cost=3179.00..3179.00 rows=100000 width=8) (actual time=127.487..127.487 rows=100000 loops=1) Buckets: 16384 Batches: 1 Memory Usage: 3907kB Buffers: shared hit=2179 -> Seq Scan on supplier (cost=0.00..3179.00 rows=100000 width=8) (actual time=0.020..82.135 rows=100000 loops=1) Buffers: shared hit=2179 Total runtime: 73907.824 ms (55 rows) COMMIT; COMMIT