Re: TODO Item - Return compressed length of TOAST datatypes

The next iteration -

Hopefully I have got the idea basically right.

I wonder if I have done the "am I a varlena" the long way.., pls advise
if so!

Cheers

Mark

Tom Lane wrote:
>
> My recollection of that discussion is that we just wanted something
> that would return the actual VARSIZE() of the datum. You're building
> something way too confusing ...
>
> A more interesting point is that the way you've declared the function,
> it will only work on text values, which is pretty limiting. Ideally
> we'd define this thing as "pg_datum_length(any-varlena-type) returns int"
> but there is no pseudotype corresponding to "any varlena type".
>
> I was thinking about this the other day in connection with my proposal
> to make something that could return the TOAST value OID of an
> out-of-line datum. I think the only non-restrictive way to do it would
> be to declare the function as taking "any", and then add a runtime check
> using the get_fn_expr_argtype() mechanism to test that what you've been
> given is in fact a varlena datatype.
>
>