Re: problematic view definition

On Sun, Feb 20, 2011 at 02:31:46PM -0500, Tom Lane wrote:

> Karsten Hilbert <Karsten.Hilbert@gmx.net> writes:
> > On Wed, Feb 09, 2011 at 11:12:01PM +0100, Karsten Hilbert wrote:
> >> Unfortunately I do not understand why PostgreSQL says
> >>
> >> psql:xx.sql:14: ERROR:  could not implement UNION
> >> DETAIL:  Some of the datatypes only support hashing, while others only support sorting.
>
> > The solution lies in these bits:
>
> >> pk_context         | integer[]                |
>
> > This data type can only be hashed.
>
> >> xmin_message_inbox | xid                      |
>
> > This data type can only be sorted.
>
> ITYM the other way round, right?

Indeed :-)

> As of 9.1 there will be support for hashing arrays, so this particular
> problem should go away without hacks.

Great. PG is getting better by the day :-)

Anyway, I consider the "explicit cast" not really that bad
of a hack.

Karsten
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