Re: [PERFORM] Strange performance boost with random()

2014-02-10 Thread Heikki Linnakangas
On 02/10/2014 09:52 PM, M Putz wrote: Hello, While analyzing performance, we encountered the following phenomenon, SELECT sum(pow(.5*generate_series,.5)) FROM generate_series(1,100); is much much (a hundred times) slower than SELECT sum(pow(random()*generate_series,.5)) F

[PERFORM] Strange performance boost with random()

2014-02-10 Thread M Putz
Hello, While analyzing performance, we encountered the following phenomenon, SELECT sum(pow(.5*generate_series,.5)) FROM generate_series(1,100); is much much (a hundred times) slower than SELECT sum(pow(random()*generate_series,.5)) FROM generate_series(1,100); and asymptotic