On Thu, Jun 11, 2015 at 12:57 PM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> alter table t alter u type uuid[] using u::uuid[];
>
> The original command worked without a USING because anything-to-text is
> considered an allowable assignment coercion; but the other way around
> requires an explicit cast.
Got it. Thanks!
I feel silly not to have tried that. Somehow I interpreted
"cannot be cast automatically to type uuid[]" as meaning
that it cannot be cast at all (and would therefore need a
more involved expression to specify how to convert it),
rather than that the cast merely needed to be explicit.