Re: PostgreSQL gaps wrt to java, and jdbc

On 7 July 2015 at 15:46, Heikki Linnakangas <hlinnaka(at)iki(dot)fi> wrote:

> On 07/07/2015 09:31 PM, Kevin Wooten wrote:
>
>> == Binary type coercion ==
>> The biggest impediment I’ve run into is the fact that PG will not
>> attempt coercion on binary types. If you specify a binary type in the
>> protocol, that’s the final word. A better system would be to have PG
>> perform the same coercion it does for text types and then send the
>> results back with coerced types, in binary; finally falling back to
>> text when binary cannot be produced. This would solve almost every
>> issue we have had to work around in the “ng” driver.
>>
>
> Can you elaborate? I'm confused, because the server can produce binary
> output for any datatype that has binary output functions. That covers all
> built-in datatypes and all extension datatypes people use in practice.
>
> What I've imagined to be a problem, though, is that you have to either
> understand the binary representation of all datatypes in the client, or you
> have to request binary for only those datatypes you can handle. And to know
> which datatype a result set's column has, you have to Describe it before
> fetching the results, which adds an extra round-trip. So it would be handy
> if the driver could provide the server a list of datatypes that should be
> sent as binary, as a one-time operation at the beginning of the session for
> example, rather than indicating for each column in each query separately.
>
>
Is there a way to get json and or xml out as binary ?

Dave Cramer