BEGIN; BEGIN EXPLAIN (ANALYZE, BUFFERS) select o_year, sum(case when nation = 'MOZAMBIQUE' 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 POLISHED STEEL' ) as all_nations group by o_year order by o_year; QUERY PLAN ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Sort (cost=2168964.82..2168966.64 rows=731 width=38) (actual time=29687.074..29687.075 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=782670 read=225010 dirtied=2537 written=8183 -> HashAggregate (cost=2168917.25..2168930.04 rows=731 width=38) (actual time=29686.994..29686.996 rows=2 loops=1) Buffers: shared hit=782667 read=225010 dirtied=2537 written=8183 -> Nested Loop (cost=501602.03..2168430.01 rows=24362 width=38) (actual time=21169.484..29615.866 rows=24415 loops=1) Buffers: shared hit=782667 read=225010 dirtied=2537 written=8183 -> Nested Loop (cost=501602.03..2161481.97 rows=24362 width=16) (actual time=21169.424..29422.348 rows=24415 loops=1) Buffers: shared hit=733837 read=225010 dirtied=2537 written=8183 -> Hash Join (cost=501602.03..2154387.70 rows=24362 width=16) (actual time=21169.384..29015.358 rows=24415 loops=1) Hash Cond: (lineitem.l_orderkey = orders.o_orderkey) Buffers: shared hit=660458 read=225010 dirtied=2537 written=8183 -> Nested Loop (cost=0.00..1650535.63 rows=401284 width=16) (actual time=0.401..6685.635 rows=400038 loops=1) Buffers: shared hit=265847 read=204520 dirtied=2537 written=8183 -> Index Only Scan using part_p_type_p_partkey_idx on part (cost=0.00..46084.18 rows=13247 width=4) (actual time=0.330..158.147 rows=13309 loops=1) Index Cond: (p_type = 'LARGE POLISHED STEEL'::text) Heap Fetches: 13309 Buffers: shared hit=8015 read=3446 written=268 -> Index Scan using lineitem_l_partkey_l_quantity_l_shipmode_idx on lineitem (cost=0.00..120.81 rows=31 width=20) (actual time=0.046..0.474 rows=30 loops=13309) Index Cond: (l_partkey = part.p_partkey) Buffers: shared hit=257832 read=201074 dirtied=2537 written=7915 -> Hash (cost=490105.28..490105.28 rows=919740 width=8) (actual time=21167.557..21167.557 rows=911892 loops=1) Buckets: 131072 Batches: 1 Memory Usage: 35621kB Buffers: shared hit=394608 read=20490 -> Hash Join (cost=138881.27..490105.28 rows=919740 width=8) (actual time=4890.937..20636.759 rows=911892 loops=1) Hash Cond: (orders.o_custkey = customer.c_custkey) Buffers: shared hit=394608 read=20490 -> Bitmap Heap Scan on orders (cost=99850.65..424632.14 rows=4598699 width=12) (actual time=3260.769..7260.845 rows=4561673 loops=1) Recheck Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared hit=255351 read=13598 -> Bitmap Index Scan on orders_o_orderdate_o_orderkey_idx (cost=0.00..98700.98 rows=4598699 width=0) (actual time=3141.972..3141.972 rows=4602796 loops=1) Index Cond: ((o_orderdate >= '1995-01-01'::date) AND (o_orderdate <= '1996-12-31'::date)) Buffers: shared read=13148 -> Hash (cost=35280.62..35280.62 rows=300000 width=4) (actual time=1629.715..1629.715 rows=299493 loops=1) Buckets: 32768 Batches: 1 Memory Usage: 10530kB Buffers: shared hit=139257 read=6892 -> Nested Loop (cost=906.17..35280.62 rows=300000 width=4) (actual time=35.107..1454.060 rows=299493 loops=1) Buffers: shared hit=139257 read=6892 -> Hash Join (cost=1.07..2.47 rows=5 width=4) (actual time=0.037..0.099 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=0.007..0.019 rows=25 loops=1) Buffers: shared hit=1 -> Hash (cost=1.06..1.06 rows=1 width=4) (actual time=0.017..0.017 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=0.013..0.015 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=33.814..270.375 rows=59899 loops=5) Recheck Cond: (c_nationkey = n1.n_nationkey) Buffers: shared hit=139255 read=6892 -> Bitmap Index Scan on customer_c_nationkey_c_custkey_idx (cost=0.00..890.09 rows=60000 width=0) (actual time=23.553..23.553 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=0.014..0.014 rows=1 loops=24415) Index Cond: (s_suppkey = lineitem.l_suppkey) Buffers: shared hit=73379 -> Index Scan using pk_nation on nation n2 (cost=0.00..0.27 rows=1 width=30) (actual time=0.004..0.005 rows=1 loops=24415) Index Cond: (n_nationkey = supplier.s_nationkey) Buffers: shared hit=48830 Total runtime: 29699.103 ms (64 rows) COMMIT; COMMIT