Re: Function args: TEXT -vs- VARCHAR?

skinner(at)britvault(dot)co(dot)uk (Craig R. Skinner) writes:
> On 2013-11-13 Wed 06:34 AM |, Adrian Klaver wrote:
>> The full SQL type syntax is allowed for input arguments and return
>> value. However, some details of the type specification (e.g., the
>> precision field for type numeric) are the responsibility of the
>> underlying function implementation and are silently swallowed (i.e.,
>> not recognized or enforced) by the CREATE FUNCTION command.

> That's rather vague..... "... some details ..."

What's ignored by CREATE FUNCTION (and, indeed, pretty much the entire
type inference mechanism) is typmod. So any parenthesized modifier for
a type name is not considered. Usually those are length/precision
constraints, but user-defined types might do something else with them.

> An explicit table of datatype & what's "silently swallowed" would be
> valuable to clarify this topic that's said to be often repeatedly asked.

Can't be asked that often, as that text has been untouched for more
than a dozen years ...

regards, tom lane