Extended Query, flush or sync ?

Hello,

It's not clear for me if I have to issue a flush or sync after each process of an extended query.

It's almost working for me only when I send a sync, but not when I send a flush. With the flush, the connection seems
freezed,or at least, I don't get any data from postgre. 


- Send the parse command
- sync
- Receive the ParseComplete
-sync
- Send the Bind
- sync
- Receive the BincComplete
- send the Execute
- receive an error => "portal xxxxxxx does not exist"


thanks,

regards,


r.