Re: count_nulls(VARIADIC "any") - Mailing list pgsql-hackers

On 2015-11-21 06:06, Tom Lane wrote:
> Marko Tiikkaja <marko@joh.to> writes:
>> Here's a patch implementing this under the name num_nulls().  For
>> January's CF, of course.
>
> What's this do that "count(*) - count(x)" doesn't?

This is sort of a lateral version of count(x); the input is a list of 
expressions rather than an expression executed over a bunch of input rows.


.m