> > > records/record/recordSchema isn't an optional field,
> > Oh. perhaps it should be.
>
> But then everything would need to be optional, as extraData fields could
> override any part of any message.
>
> I would think it's quite likely that someone will define an SQL query
> extension, where you pass a statement in, and it executes it (In
> the same vein as ZSQL).  So do we make the query field optional too?

I don't buy the analogy.  RecordSchema says what schema the client wants the
records in.  If it were optional, by omiting it you would be leaving it to
the server to choose. That's straight out of Z39.50.  You can omit it
without having to include an otherInfo. The semantics of omission are clear.
Omiting the query would be quite different.  I would think that before we
would take the approach of allowing the query to be omitted so that an sql
query could instead be supplied in an "extra" field, instead we would keep
the query parameter mandatory but add a query-type parameter.

--Ray