On Fri, Dec 8, 2023 at 1:39 AM Andrew Dunstan <and...@dunslane.net> wrote: > > > On 2023-12-07 Th 03:37, Junwang Zhao wrote: > > > > The point of this refactor (from my view) is to make it possible to add new > > copy handlers in extensions, just like access method. As Andres suggested, > > a system catalog like *pg_copy_handler*, if we split TO and FROM into two > > sets of routines, does that mean we have to create two catalog( > > pg_copy_from_handler and pg_copy_to_handler)? > > > > Surely not. Either have two fields, one for the TO handler and one for > the FROM handler, or a flag on each row indicating if it's a FROM or TO > handler.
True. But why do we need a system catalog like pg_copy_handler in the first place? I imagined that an extension can define a handler function returning a set of callbacks and the parser can lookup the handler function by name, like FDW and TABLESAMPLE. Regards, -- Masahiko Sawada Amazon Web Services: https://aws.amazon.com
