Re: Binary tx format for an array?

[Dave Cramer <pg(at)fastcrypt(dot)com>]

On 23-Jun-06, at 4:32 PM, Mark Lewis wrote:

> > Hmmm maybe I should read before sending. It appears that both input,
> > and output can be text. The only catch with output is that you have
> > to do a describe first to get the types. This may negate any gains on
> > small result sets, but certainly for large ones it would help.
>
> Disclaimer: this is my first real trip through the v3 protocol and the
> JDBC driver source in general.  So take anything below with several
> grains of salt.
>
> As far as I can tell from reading the JDBC CVS code, the sequence for
> preparing and executing a statement for the first time is:
>
> PREPARE            (name=my_statement)
> DESCRIBE STATEMENT (name=my_statement)
> SYNC/FLUSH
> Read Responses
>
> BIND               (portal=my_portal)
> DESCRIBE PORTAL    (name=my_portal)
> EXECUTE            (portal=my_portal)
> SYNC/FLUSH
> Read Responses
>
> So it seems that we could do all text, mixed or all binary parameters
> without adding a round trip, because we already do an extra round trip
> when a statement is first prepared and we already know all of the
> parameter types.

Yup, you could, however the real win here is on parsing the return  
parameters, going from object to string is not terribly expensive.

Network times are probably a red herring.

> We could do all text or all binary outputs without adding a round trip
> as well, because you can globally set the output format, but to do  
> mixed
> outputs we'd need to execute the DESCRIBE PORTAL to get the return
> types, and then (not sure?) execute BIND again with different format
> parameters?
Yes, you can do binary results, but consider what happens if someone  
returns a type the driver doesn't know about ?
> -- Mark Lewis