Re: AssertArg failure in src/backend/executor/functions.c:check_sql_fn_retval()

On 2016-03-27 16:40, Tom Lane wrote:
> Hm.  I would argue that it should have rejected CAST(NULL AS ANYARRAY).
> That's a pseudotype and so there should never be an actual value of that
> type, not even a null value.

I'm a little confused about what you mean here. I thought reject was 
exactly what's happening; normally you'd get "ERROR:  return type 
anyarray is not supported for SQL functions".

If you mean specifically to forbid CAST(NULL AS ANYARRAY) in general 
then I'd like to point out that there are columns of type anyarray, at 
least pg_catalog.pg_statistic.stavalues1 is, so the cast is not the only 
way to trigger this.