Michael Meskes <meskes@postgresql.org> writes:
> Can I safely assume that the OID of the standard data types remain the same
> for future releases? And of course that they are the same for every
> installation?
They are fixed in any one version, and really are not very likely to
change across versions either. But I suppose it could happen.
> I've been send a patch to speed up ecpg significantly by not looking up
> datatypes everytime. As it is written right now it works by har coding some
> types. I wonder if this will create problems.
Exactly how "hard coded" do you mean? If you #include "catalog/pg_types.h"
and use the OID #defines therein, you're not doing any worse than a lot
of places in the backend. At worst you'd create a cross-major-version
incompatibility for ecpg.
regards, tom lane