BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'MOROCCO' 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 = 'PROMO BURNISHED NICKEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2196525.36..2196527.18 rows=728 width=38) (actual time=49336.280..49336.280 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=700941 read=305220 dirtied=776 written=26 -> HashAggregate (cost=2196478.01..2196490.75 rows=728 width=38) (actual time=49336.106..49336.108 rows=2 loops=1) Buffers: shared hit=700938 read=305220 dirtied=776 written=26 -> Nested Loop (cost=497071.39..2195983.91 rows=24705 width=38) (actual time=29984.047..49229.056 rows=24557 loops=1) Buffers: shared hit=700938 read=305220 dirtied=776 written=26 -> Nested Loop (cost=497071.39..2188938.05 rows=24705 width=16) (actual time=29983.962..48832.096 rows=24557 loops=1) Buffers: shared hit=651824 read=305220 dirtied=776 written=26 -> Hash Join (cost=497071.39..2181741.55 rows=24713 width=16) (actual time=29983.908..47879.053 rows=24557 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=578030 read=305220 dirtied=776 written=26 -> Nested Loop (cost=0.00..1682378.39 rows=408929 width=16) (actual time=0.666..16563.707 rows=400762 loops=1) Buffers: shared hit=260635 read=209042 dirtied=758 written=3 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..47001.38 rows=13553 width=4) (actual time=0.542..559.923 rows=13343 loops=1) Index Cond: (p_type = 'PROMO BURNISHED NICKEL'::text) Heap Fetches: 13343 Buffers: shared hit=2410 read=9054 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..120.36 rows=31 width=20) (actual time=0.128..1.181 rows=30 loops=13343) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=258225 read=199988 dirtied=758 written=3 -> Hash (cost=485672.01..485672.01 rows=911951 width=8) (actual time=29979.302..29979.302 rows=911930 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35623kB Buffers: shared hit=317392 read=96178 dirtied=18 written=23 -> Hash Join (cost=136270.05..485672.01 rows=911951 width=8) (actual time=8125.808..29057.515 rows=911930 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=317392 read=96178 dirtied=18 written=23 -> Bitmap Heap Scan on orders (cost=97239.43..420422.79 rows=4559757 width=12) (actual time=4239.069..11938.157 rows=4561664 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=207333 read=60088 dirtied=18 written=23 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..96099.49 rows=4559757 width=0) (actual time=4081.640..4081.640 rows=4584480 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=572 read=12062 written=21 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=3886.386..3886.386 rows=299493 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10530kB Buffers: shared hit=110059 read=36090 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=48.604..3643.655 rows=299493 loops=1) Buffers: shared hit=110059 read=36090 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.055..0.128 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=0.008..0.024 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.026..0.026 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..0.023 rows=1 loops=1) Filter: (r_name = 'AFRICA'::bpchar) Rows Removed by Filter: 4 Buffers: shared hit=1 -> Bitmap Heap Scan on customer (cost=905.09..6455.63 rows=60000 width=8) (actual time=39.952..706.320 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=110057 read=36090 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=29.068..29.068 rows=59899 loops=5) Index Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=7 read=826 -> Index Scan using pk_supplier on supplier (cost=0.00..0.28 rows=1 width=8) (actual time=0.035..0.036 rows=1 loops=24557) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=73794 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.011..0.012 rows=1 loops=24557) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=49114 Total runtime: 49350.252 ms (64 rows) COMMIT; COMMIT