Re: TODO Item: Allow pg_hba.conf to specify host names along with IP addresses

On Fri, 13 Jun 2008 16:14:13 -0400 Alvaro Herrera wrote:

> Andrew Sullivan wrote:
> 
> > This is because DNS RRs have a TTL on them, so looking up the host at
> > any moment other than when you're actually doing the authentication is
> > prone to error.
> 
> Perhaps the solution to this problem is to do the lookups and store the
> TTL of each answer.  At the time of actually checking you need only get
> a new answer for those that expired.

That's too much overhead in the postmaster.
A better way would be some documentation how one can improve the DNS
performance, like using an external DNS cache ect.

I would also like to see a note that the DNS lookup could seriously
slow down the authentication process.


Kind regards

--             Andreas 'ads' Scherbaum
German PostgreSQL User Group