Re: System vs non-system casts

Alvaro Herrera <alvherre@dcc.uchile.cl> writes:
> On Tue, Apr 12, 2005 at 05:04:03PM -0000, Andrew - Supernews wrote:
>> Checking the OID might be sufficient if it were possible to make the OID
>> counter restart at some value known to be greater than any datlastsysoid,
>> rather than restarting at BootstrapOid.

> In fact AFAICT it does start at BootstrapObjectIdData, which is 16384 by
> default.

This line of thought is pretty much a non-starter, because many "system"
objects are created after the initial bootstrap phase, during standalone
backend sessions that are not fundamentally different from ordinary
operations.  For instance I don't think we want a solution in which
casts created as part of the information_schema couldn't be marked as
builtins.  (Right at the moment there don't seem to be any such casts,
but certainly there might someday be a need for one.)

Alvaro's "pg_cast.castissystem" idea can be made to work with this,
if necessary by brute-force UPDATEs of pg_cast.  Playing games with
the values of OIDs can't ...
        regards, tom lane