Richard Hayward <richard(at)tortoise(dot)demon(dot)co(dot)uk> writes:
> Is it possible to prevent a user from changing their password?
No.
> I have a database with a 'Guest' account, that will have limited
> access. I don't want any of my guests to change the Guest account
> password.
Perhaps you should use something other than password authentication
for the guest account.
regards, tom lane