| From: | Greg Stark <stark(at)mit(dot)edu> |
|---|---|
| To: | Josh Berkus <josh(at)agliodbs(dot)com> |
| Cc: | Mark Kirkwood <mark(dot)kirkwood(at)catalyst(dot)net(dot)nz>, Robert Haas <robertmhaas(at)gmail(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: ANALYZE sampling is too good |
| Date: | 2013-12-09 18:56:48 |
| Message-ID: | CAM-w4HMrZTy8F56hbGpSEyrQ9hwiuuTm1pm6amh=MgK1yKhzrg@mail.gmail.com |
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| Lists: | pgsql-hackers |
On Mon, Dec 9, 2013 at 6:54 PM, Greg Stark <stark(at)mit(dot)edu> wrote:
>
> This "some math" is straightforward basic statistics. The 95th
> percentile confidence interval for a sample consisting of 300 samples
> from a population of a 1 million would be 5.66%. A sample consisting
> of 1000 samples would have a 95th percentile confidence interval of
> +/- 3.1%.
Incidentally I got this using an online sample size calculator. Google
turns up several but this one seems the easiest to use:
http://www.raosoft.com/samplesize.html
--
greg
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