Re: Query optimizer 8.0.1 (and 8.0)

On Mon, Feb 07, 2005 at 11:27:59 -0500,
pgsql(at)mohawksoft(dot)com wrote:
>
> It is inarguable that increasing the sample size increases the accuracy of
> a study, especially when diversity of the subject is unknown. It is known
> that reducing a sample size increases probability of error in any poll or
> study. The required sample size depends on the variance of the whole. It
> is mathmatically unsound to ASSUME any sample size is valid without
> understanding the standard deviation of the set.

For large populations the accuracy of estimates of statistics based on random
samples from that population are not very sensitve to population size and
depends primarily on the sample size. So that you would not expect to need
to use larger sample sizes on larger data sets for data sets over some
minimum size.