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 = 'AMERICA' and o_orderdate >= date '1995-01-01' and o_orderdate < date '1995-01-01' + interval '1 year' group by n_name order by revenue desc; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=1860150.21..1860150.28 rows=25 width=34) (actual time=13763.410..13763.412 rows=5 loops=1) Sort Key: (sum((lineitem.l_extendedprice * (1::double precision - lineitem.l_discount)))) Sort Method: quicksort Memory: 25kB Buffers: shared hit=2361091 read=354324 dirtied=88 written=4703 -> HashAggregate (cost=1860149.38..1860149.63 rows=25 width=34) (actual time=13763.336..13763.339 rows=5 loops=1) Group Key: nation.n_name Buffers: shared hit=2361088 read=354324 dirtied=88 written=4703 -> Hash Join (cost=92028.90..1859420.31 rows=72907 width=34) (actual time=2265.401..13686.810 rows=72820 loops=1) Hash Cond: ((lineitem.l_suppkey = supplier.s_suppkey) AND (customer.c_nationkey = supplier.s_nationkey)) Buffers: shared hit=2361088 read=354324 dirtied=88 written=4703 -> Nested Loop (cost=87349.90..1840328.16 rows=1824545 width=46) (actual time=2195.054..12992.772 rows=1817944 loops=1) Buffers: shared hit=2358906 read=354324 dirtied=88 written=4703 -> Hash Join (cost=87349.33..388966.10 rows=456248 width=38) (actual time=2194.994..6112.944 rows=454876 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=256339 read=150081 dirtied=88 written=4289 -> Bitmap Heap Scan on orders (cost=48307.17..336806.80 rows=2281242 width=8) (actual time=943.249..3914.501 rows=2277764 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate < '1996-01-01 00:00:00'::timestamp without time zone)) Heap Blocks: exact=254261 Buffers: shared hit=146500 read=113982 dirtied=88 written=719 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..47736.85 rows=2281242 width=0) (actual time=851.790..851.790 rows=2284654 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate < '1996-01-01 00:00:00'::timestamp without time zone)) Buffers: shared hit=375 read=5846 written=526 -> Hash (cost=35292.17..35292.17 rows=300000 width=38) (actual time=1247.484..1247.484 rows=299436 loops=1) Buckets: 524288 Batches: 1 Memory Usage: 25151kB Buffers: shared hit=109839 read=36099 written=3570 -> Nested Loop (cost=905.25..35292.17 rows=300000 width=38) (actual time=22.183..1125.877 rows=299436 loops=1) Buffers: shared hit=109839 read=36099 written=3570 -> Nested Loop (cost=0.14..13.95 rows=5 width=30) (actual time=0.056..0.119 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=0.013..0.036 rows=25 loops=1) Buffers: shared hit=2 -> Materialize (cost=0.00..1.07 rows=1 width=4) (actual time=0.001..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=0.017..0.018 rows=1 loops=1) Filter: (r_name = 'AMERICA'::bpchar) Rows Removed by Filter: 4 Buffers: shared hit=1 -> Bitmap Heap Scan on customer (cost=905.11..6455.64 rows=60000 width=8) (actual time=19.541..211.761 rows=59887 loops=5) Recheck Cond: (c_nationkey = nation.n_nationkey) Heap Blocks: exact=145102 Buffers: shared hit=109836 read=36099 written=3570 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.11 rows=60000 width=0) (actual time=12.836..12.836 rows=59887 loops=5) Index Cond: (c_nationkey = nation.n_nationkey) Buffers: shared hit=7 read=826 written=88 -> Index Scan using pk_lineitem on lineitem (cost=0.56..3.03 rows=15 width=16) (actual time=0.012..0.014 rows=4 loops=454876) Index Cond: (l_orderkey = orders.o_orderkey) Buffers: shared hit=2102567 read=204243 written=414 -> Hash (cost=3179.00..3179.00 rows=100000 width=8) (actual time=69.426..69.426 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=0.008..41.094 rows=100000 loops=1) Buffers: shared hit=2179 Planning time: 6.848 ms Execution time: 13769.354 ms (56 rows) COMMIT; COMMIT