Re: Can we get SQL Server-like cross database queries

On Thu, Jun 4, 2020 at 12:56 AM Laurenz Albe <laurenz(dot)albe(at)cybertec(dot)at>
wrote:

> On Thu, 2020-06-04 at 16:41 +1200, Thomas Munro wrote:
> > There's no doubt it's useful, and it's also part of the SQL spec,
> > which says you can do catalog.schema.table. I would guess that we
> > might get that as a byproduct of any project to make PostgreSQL
> > multithreaded. That mountain moving operation will require us to get
> > rid of all the global state that currently ties a whole process to one
> > session and one database, and replace it with heap objects with names
> > like Session and Database that can be passed around between worker
> > threads.
>
> I am -1 on cross-database queries.
>
> I think it is a desirable feature to have databases isolated from
> each other, so you don't have to worry about a permission you forgot
> that allows somebody to access a different database.
>

Perhaps make it a new right that can be granted and it is disabled by
default.

Superusers could have it by default.

ALTER USER foo WITH CROSSDB | NOCROSSDB

Obviously there is much more to flesh out than this.

-m