Re: New pg_pwd patch and stuff

> 
> Sorry for the response delay.  I was out of town.
> 
> I don't believe that pg_user needs to be readable by users in general.  They
> don't really need to know who else has access to the DB, and they certainly 
> don't need to know what access they do have (e.g. usesuper and createuser).
> 
> As for the suggestion that the passwords don't need to be in the cache, this is
> incorrect.  For the system (as I have designed it) to work, the postmaster must
> check at each login to see if the user has a password.  Using another relation
> along with a select to look up the password from pg_user is not as efficient,
> and it is not possible from the postmaster.  In order for this to work, each
> time that pg_user or pg_password (if we use a 2nd relation) is modified, a join
> must be performed between the two (essentially perform a select on a view that
> performs the join) before the data can be copied to the pg_pwd file for the
> postmaster to use.  I don't even know if the copy command will work with a view.
> For these reasons I still believe that pg_user should just remain non-accessible
> to the general public.
> 
> Todd A. Brandys
> 

Can't we create a function to get the info:

create function get_passwd returns text as
	'select passwd from pg_password'
	language 'sql';

And this will return a null for password not found, and a valid password
for others.  I don't think a view will work.  I think you would have to
do a SELECT ... INTO and do a COPY from that temp table.  Sounds like
some work.

Now this is done ONLY when a password changed is made, or a user is
deleted or added.  Is that correct?  Doesn't sound like too much of a
hit to me.  Now if it was done for every connection, we would have big
troubles.


-- 
Bruce Momjian
maillist@candle.pha.pa.us