Michael Fuhr <mike@fuhr.org> writes:
> for example, one may write 'mytable'::regclass to get the OID
> of table mytable, rather than SELECT oid FROM pg_class WHERE
> relname = 'mytable'.
> To get the OID, don't we then need to cast to the oid type?
If you want to see it as a numeric value, yeah, but you can for example
compare it to an OID column without doing that.
SELECT attname FROM pg_attribute WHERE attrelid = 'mytable'::regclass;
Most of the time when I'm using a regxxx cast, it's because I *don't*
want to be bothered with the numeric value.
regards, tom lane