two question about sql-mode

[Luca Ferrari]

Hi all,
I've two questions about the sql mode.
The first one is that onn my linux box I've Oracle SQL Developer, but
not sqlplus, and when I try to connect to an oracle database but of
course I got a "no sqlplus found" error, and therefore I would like to
know if it is possible to use the sqldeveloper as intermediate library
to connect thru Emacs, and if someone can point me to the right
configuration.

The second is about PostgreSQL: if I get it right it seems that C-c
C-c (send-paragraph) works only for the sqli buffer, that is for
Oracle. Is there any way to use something similar via libpq?

Thanks,
Luca