Re: host name support in pg_hba.conf

Peter Eisentraut <peter_e@gmx.net>

From: Peter Eisentraut <peter_e@gmx.net>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: KaiGai Kohei <kaigai@ak.jp.nec.com>, pgsql-hackers@postgresql.org
Date: 2010-10-13T19:37:03Z
Lists: pgsql-hackers
On tis, 2010-10-12 at 17:03 -0400, Tom Lane wrote:
> Oh, I had an idea for a small improvement to this.  It doesn't seem
> unlikely that pg_hba.conf could contain multiple entries with the same
> host name (but, presumably, different user and/or database names).  As
> this is coded, you'll do a forward DNS lookup for each one until
> finding
> the complete match.  You could easily prevent that by adding an
> additional cache field to struct Port, along the lines of
>         +1 = remote_hostname is known to resolve to client's IP
> address
>         -1 = remote_hostname is known NOT to resolve to client's IP
> address
>         0 = we have not done the forward DNS lookup yet.
> With this additional field we could guarantee to do not more than two
> DNS lookups per connection attempt.

That's a very good idea.  I will revise my patch.