Re: DRDA, network protocol, and documentation

On Thu, 2002-02-07 at 15:35, Brian Bruns wrote:
> On 7 Feb 2002, Hannu Krosing wrote:
> 
> 
> > What is the relation of DRDA to SQL/CLI (SQL Call Level Interface, part
> > 3 of the standard) ?
> 
> DRDA, SQL 9x, and SQL/CLI (ODBC) form a complimentary set of standards.
> 
> SQL 9x obviously specifies the SQL language and constructs.  SQL/CLI 
> addressses application portability with an API.  DRDA on the other hand is 
> a bits on the wire protocol.  So one would have a program using the ODBC 
> API to send DRDA over the network to invoke SQL on the server.

But I guess that you can't fake PREPARE/EXECUTE on client side anymore
if you want to be DRDA compatible?

Or is DRDA so low-level that it does not care what info it carries ?

Does DRDA have standard representation of datatypes on wire ? 

If so, how will postgres extendable datatypes fit in there ?

I know that postgres's system tables have two sets of type i/o functionstypinput     | regproc  | typoutput    |
regproc | typreceive   | regproc  | typsend      | regproc  | 
 

which are currently initialised to the same real functions

hannu=# select count(*) from pg_type where typoutput <> typsend or
typinput <> typreceive;count 
-------    0
(1 row)

I suspect thet the typreceive and typsend were planned for some common
network representation, but such usage has probaly gone untested for a
very long time.

----------------
Hannu