Defaults:bob runas_default=oracle
would achieve the desired result ofr the preceding sudoers fragment.
+Q) When I try to run sudo via ssh, I get the error:
+ sudo: no tty present and no askpass program specified
+A) ssh does not allocate a tty by default when running a remote command.
+ Without a tty, sudo cannot disable echo when prompting for a password.
+ You can use ssh's "-t" option to force it to allocate a tty.
+ Alternately, if you do not mind your password being echoed to the
+ screen, you can use the "visiblepw" sudoers option to allow this.
+
Q) How do you pronounce `sudo'?
A) The official pronunciation is soo-doo (for su "do"). However, an
alternate pronunciation, a homophone of "pseudo", is also common.