Re: [Re] Re: PREPARE and transactions

Jeroen T. Vermeulen wrote:
> On Sun, Jul 04, 2004 at 02:33:53PM +1200, Oliver Jowett wrote:
>  
> 
>>Consider SET client_encoding then..
> 
> 
> Does that really affect most middleware?  In my situation for instance,
> what goes through the connection either way is "just bytes" to the
> middleware.  Its interpretation is a client matter.  So to me this is a
> client application thing (though of course lower-level than normal SQL)
> and it's also fully transactional.

It certainly affects the JDBC driver -- the native String representation 
in Java is UTF-16, so the driver transcodes between that and 
client_encoding for parameterized queries and query results involving 
strings.

With the V2 protocol, if the application issues a SET client_encoding, 
suddenly that transcoding breaks without warning.

With the V3 protocol, at least the driver can notice the change (via a 
ParameterStatus message) and complain loudly. It could track the change, 
in theory, but since the choice of client_encoding is an implementation 
detail for the JDBC driver and everything is going to end up as UTF-16 
anyway, there's no real point in allowing it.

So at least from that point of view, client_encoding is very much a 
protocol-level thing. Much as I see PREPARE :)

-O