Re: Why don't we allow DNS names in pg_hba.conf?

Jon Jensen <jon@endpoint.com> writes:
> (1) What Tom proposed is that we store the hostname and do a new DNS 
> lookup for every connection. That could be useful in certain situations, 
> but I wouldn't use it for a busy production server. The additional time 
> for DNS lookups (even with a fast local caching nameserver) would not be a 
> price I'd want to pay for the convenience.

Can you demonstrate that this is actually a serious concern next to the
total time spent launching a backend?  I can't measure any real change
in total time for "psql -l" when log_hostname is enabled, which should
be a comparable hit.

I started out proposing a one-line change.  The odds of this ever
getting done drop by an order of magnitude every time someone proposes
another order-of-magnitude increase in the work required...
        regards, tom lane