Re: Feature request for count_estimate(samplesize) aggregate or SAMPLE keyword - Mailing list pgsql-general

I am not aware of this, sounds like what I want. Will look into it. Thanks!

Am 01.09.22 um 03:47 schrieb Tom Lane:
> Torge <torgato@posteo.de> writes:
>> Now I would like to humbly propose a feature that gives an easy way to
>> get a quick count estimate for any condition - index based or not -
>> based on a random sample of rows, that does not require a custom
>> function creation or complex SQL statement
> Can't you do that already using TABLESAMPLE?  For example, to
> use a 1% sample:
>
> select count(*) * 100 from mytab tablesample system(1) where <condition>;
>
> You do have to remember to multiply by the factor corresponding
> to your sample rate, but aside from that annoyance this (a)
> already exists, (b) is SQL-standard, and (c) can be adapted to
> a lot of other kinds of analysis besides plain count(*).
>
>             regards, tom lane