Re: PostgreSQL gaps wrt to java, and jdbc - Mailing list pgsql-jdbc

On Jul 7, 2015, at 1:26 PM, Dave Cramer <davecramer@gmail.com> wrote:

On 7 July 2015 at 16:24, Heikki Linnakangas <hlinnaka@iki.fi> wrote:

On 07/07/2015 11:04 PM, Kevin Wooten wrote:

As far as “coercion" goes maybe a better term would be “deduction”.
There are numerous cases where it would be great if we could send the
server a “don’t care” type and just a binary format.   Instead we
have to specify a type and format together. Doing this causes issues
in edge cases (e.g. strings coming back padded because we specified
varchar but the column was text).

Oh, are you talking about query parameters, sent from the client to the server? The type OID and format code are not actually sent in the same message - you give the OID in the Parse message and the format code in Bind. You don't have to specify the OID in the Parse if you don't want to, and the server will deduce the most sensible one from the query context. After the Parse, you can find out what the server deduced by sending a ParameterDescription message, and then form the appropriate binary representation for the deduced type, and send it with Bind. Am I missing something?

I think Kevin was hoping the server would just "figure it out" without all the back and forth. 

Dave Cramer