Thread: BUG #1110: psql -h localhost consults the nameservice

The following bug has been logged online:

Bug reference:      1110
Logged by:          Michael Enke

Email address:      michael.enke@wincor-nixdorf.com

PostgreSQL version: 7.4

Operating system:   Linux

Description:        psql -h localhost consults the nameservice

Details:

If I call "psql -h localhost" it is very slow
compared to "psql -h 127.0.0.1" since for "localhost"
the nameservice is consulted.

It is reproducable best in a loop. Call 50 times:
"psql -h localhost" takes 6 seconds
"psql -h 127.0.0.1" takes 0.6 seconds
This was not the case for psql from version 7.3
May be this has something to do with changes for IP v6.

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Thank you.

PostgreSQL Bugs List wrote:
>
> The following bug has been logged online:
>
> Bug reference:      1110
> Logged by:          Michael Enke
>
> Email address:      michael.enke@wincor-nixdorf.com
>
> PostgreSQL version: 7.4
>
> Operating system:   Linux
>
> Description:        psql -h localhost consults the nameservice
>
> Details:
>
> If I call "psql -h localhost" it is very slow
> compared to "psql -h 127.0.0.1" since for "localhost"
> the nameservice is consulted.
>
> It is reproducable best in a loop. Call 50 times:
> "psql -h localhost" takes 6 seconds
> "psql -h 127.0.0.1" takes 0.6 seconds
> This was not the case for psql from version 7.3
> May be this has something to do with changes for IP v6.

Odds are your nameserver is messed up.  Try:

    host localhost

and see if that is slow.  I bet it is.

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
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"PostgreSQL Bugs List" <pgsql-bugs@postgresql.org> writes:
> If I call "psql -h localhost" it is very slow
> compared to "psql -h 127.0.0.1" since for "localhost"
> the nameservice is consulted.

This is not a bug; it's supposed to do that.  If you don't like it,
reconfigure your name service (see /etc/nsswitch.conf and /etc/resolv.conf).

            regards, tom lane

Tom Lane wrote:
> "PostgreSQL Bugs List" <pgsql-bugs@postgresql.org> writes:
>
>>If I call "psql -h localhost" it is very slow
>>compared to "psql -h 127.0.0.1" since for "localhost"
>>the nameservice is consulted.
>
>
> This is not a bug; it's supposed to do that.  If you don't like it,
> reconfigure your name service (see /etc/nsswitch.conf and /etc/resolv.conf).
>
>             regards, tom lane


Ok, I'm not sure if this is a bug or not.
But definitively for postgresql version 7.3.3 on RedHat Linux,
for "localhost" it was not contacting the name service.
This difference I noticed.

Regards,
Michael