The normal input function for variables with properties of {internallength!= variable, storage=plain/main}, the return type will be Datum.
The definition of Datum is "unsigned __int64" which may only consist the address of pointed data.
For data with variable length, the length of the data is also needed, so Datum type would be not enough since it only provide a pointer to the data.
So what should I do if I would have a TOAST enabled user defined data types, should I use other type such as struct varlena as return type??
Thanks so much!!