It's rumoured that Hiroshi Inoue once said:
> Tom Lane wrote:
>>
>> "Dave Page" <dpage@vale-housing.co.uk> writes:
>> > No, but with them we can avoid cluttering the wire protocol with
>> > fields for all this, and the JDBC required data. With 2 numeric
>> > columns (attrelid, attnum), any application/interface can query the
>> > system catalogs easily for whatever extra info they like.
>>
>> This is my feeling also. We shouldn't try to guess in the protocol
>> exactly what set of information will be wanted by a frontend; we
>> should just provide the catalog keys needed to look up whatever is
>> wanted.
>
> Does looking up by the catalog keys take no cost ?
Obviously there is cost, but doing a lookup only on demand, has got to be
cheaper in the long run than including the entire column definition in the
message whether it's wanted or not?
Regards, Dave.