Re: Review: listagg aggregate

2010/2/1 Thom Brown <thombrown@gmail.com>:

> I noticed that the regression test results don't include the following case:
>
> select string_agg(a) from (values(null),(null)) g(a);
>
> There is one similar where a delimiter is provided.
>
> Which leads me to ask for clarification, would it be safe to assume that
> string_agg can never itself return null?

if all values are null, then result is null.

Pavel