Identifying casts
Is there any way of identifying whether a cast was built-in or is
user-defined?
I am tempted to just assume that if the cast is to/from a user-defined
type or uses a user-defined function that it is user-defined. I suspect
though that a user could define a new cast on pre-defined types using a
pre-defined function.
__
Marc
Hello
you can use oid. When oid is greather than some constant, then cast is
custom. The constant is different on any postgresq versions.
You can get it on clean postgres with statement
select max(oid) from pg_cast;
Regards
Pavel Stehule
Show quoted text
On 07/12/2007, Marc Munro <marc@bloodnok.com> wrote:
Is there any way of identifying whether a cast was built-in or is
user-defined?I am tempted to just assume that if the cast is to/from a user-defined
type or uses a user-defined function that it is user-defined. I suspect
though that a user could define a new cast on pre-defined types using a
pre-defined function.__
Marc
Marc Munro <marc@bloodnok.com> writes:
Is there any way of identifying whether a cast was built-in or is
user-defined?
It's not easy. I'd suggest following the same heuristic pg_dump
does, which is that if any of the source type, target type, or
underlying function is considered user-defined, then the cast is too.
regards, tom lane