(also commented on IMPALA-4326)
For this functionality, I'd prefer to follow what Postgres does and use its
well-named functions like string_to_array().
This becomes powerful when using the unnest() table function, which is
defined and is part of the ANSI/ISO SQL:2016 spec (vs the non-standard
lateral view explode Hive syntax).
with t as (
select
42 as id,
'1,2,3,4,5,6'::text as string_array
)
select
t.id,
u.l
from t, unnest(string_to_array(t.string_array,',')) as u(l);
id | l
----+---
42 | 1
42 | 2
42 | 3
42 | 4
42 | 5
42 | 6
On Mon, Jun 19, 2017 at 7:40 AM, Alexander Behm <alex.b...@cloudera.com>
wrote:
> Yes and no. Extending the UDF framework might be hard, but I think
> implementing a built-in split() is feasible. We already have a built-in
> Expr that returns an array type to implement unnest.
>
> On Mon, Jun 19, 2017 at 6:22 AM, Vincent Tran <vtt...@cloudera.com> wrote:
>
> > This request appears to be blocked by the current UDF framework's
> > limitation.
> > As far as I can tell, functions can still only return simple scalar
> types,
> > right?
> >
>
