COUNT(DISTINCT varargs...) can be used either as a scalar aggregate
function or a group aggregate function. For example
SELECT COUNT(DISTINCT expr1, expr2, ...)
FROM TABLE;
returns a single value. It can be used with GROUP BY to produce a
distinct count per group. I think it would be useful to ha
> Aren't SELECT DISTINCT and COUNT DISTINCT just condensed variants of a GROUP
> BY query? Do they need to be exposed as standalone kernels?
I listed SELECT DISTINCT and COUNT DISTINCT in the document only as
examples of SQL statements that take a variable number of arguments,
not to imply that t
Aren't SELECT DISTINCT and COUNT DISTINCT just condensed variants of a
GROUP BY query? Do they need to be exposed as standalone kernels?
Le 18/06/2021 à 00:58, Ian Cook a écrit :
Arrow developers,
A couple of recent PRs have added new variadic scalar kernels to the
Arrow C++ library (ARROW
hi Ian — I agree with implementing these functions with
varargs/variadic inputs (this was my original intent when drafting
compute/kernel.h and related machinery last year).
As one nuance with the way that things work right now, the type
matching infrastructure isn't necessarily able to determine
Arrow developers,
A couple of recent PRs have added new variadic scalar kernels to the
Arrow C++ library (ARROW-12751, ARROW-12709). There were some
questions raised in comments on Jira and GitHub about whether these
could instead be implemented as unary or binary kernels that take
ListArray or St
