Re: Numeric performances
От | PFC |
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Тема | Re: Numeric performances |
Дата | |
Msg-id | op.ttd6dlbgcigqcu@apollo13 обсуждение исходный текст |
Ответ на | Re: Numeric performances (Lincoln Yeoh <lyeoh@pop.jaring.my>) |
Ответы |
Re: Numeric performances
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Список | pgsql-general |
>> It is. But why do you care? You either have the correctness that >> NUMERIC gives, or you don't. > > I suspect it's still useful to know what order of magnitude slower it > is. After all if it is 1000x slower (not saying it is), some people may > decide it's not worth it or roll their own. > > Any hints/gotchas for/when doing such performance tests? forum_bench=> CREATE TEMPORARY TABLE test AS SELECT a::FLOAT AS f, a::NUMERIC AS n, a::INTEGER AS i, a::BIGINT AS b FROM generate_series( 1,100000 ) AS a; SELECT Temps : 1169,125 ms forum_bench=> SELECT sum(i) FROM test; Temps : 46,589 ms forum_bench=> SELECT sum(b) FROM test; Temps : 157,018 ms forum_bench=> SELECT sum(f) FROM test; Temps : 63,865 ms forum_bench=> SELECT sum(n) FROM test; Temps : 124,816 ms SELECT * FROM test ORDER BY i LIMIT 1; SELECT * FROM test ORDER BY b LIMIT 1; SELECT * FROM test ORDER BY f LIMIT 1; SELECT * FROM test ORDER BY n LIMIT 1; Temps : 68,996 ms Temps : 68,917 ms Temps : 62,321 ms Temps : 71,880 ms BEGIN; CREATE INDEX test_i ON test(i); CREATE INDEX test_b ON test(b); CREATE INDEX test_f ON test(f); CREATE INDEX test_n ON test(n); ROLLBACK; CREATE INDEX Temps : 102,901 ms CREATE INDEX Temps : 123,406 ms CREATE INDEX Temps : 105,255 ms CREATE INDEX Temps : 134,468 ms
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