Thread: Default value after table create

Default value after table create

From
"Robson"
Date:
 
    With set default value, after  table create ?
 
    with pgAdmin II , psql, or etc...
 
    Regards,
 
    Robson
   

Re: Default value after table create

From
"Florian Helmberger"
Date:
Hi.
 
alter table <table_name> alter column <column_name> add default <default>;
 
Cheers,
Florian
-----Original Message-----
From: pgsql-admin-owner@postgresql.org [mailto:pgsql-admin-owner@postgresql.org]On Behalf Of Robson
Sent: Friday, June 21, 2002 2:13 PM
To: pgsql-admin@postgresql.org
Subject: [ADMIN] Default value after table create
Importance: High

 
    With set default value, after  table create ?
 
    with pgAdmin II , psql, or etc...
 
    Regards,
 
    Robson
   

Slow Remote connection

From
Jean-Arthur Silve
Date:
Hi !

I have a httpd server on one server, and PostgresQL 7.2 on a second server
(P4 1.7 Ghz / Linux ) on a local network.

When there are about 20 (and more ) connection on the DB, the remote
connecxtion to the DB from the web server is very long (about 5-10 sec)
before have the prompt.

On the local machine, it's near immediate.

I use IP authentification (no username/password).

Local network seems ok (I can connect to web sites etc..fast !)

Any clue ??

Thank you for your help !

jean-arthur




Re: Slow Remote connection

From
Tom Lane
Date:
Jean-Arthur Silve <jeanarthur@eurovox.fr> writes:
> I have a httpd server on one server, and PostgresQL 7.2 on a second server
> (P4 1.7 Ghz / Linux ) on a local network.

> When there are about 20 (and more ) connection on the DB, the remote
> connecxtion to the DB from the web server is very long (about 5-10 sec)
> before have the prompt.

> On the local machine, it's near immediate.

Weird.  Perhaps something wrong with your DNS setup, causing it to take
a long time to resolve the name of the other machine?  Anyway I'd
suspect that the problem is not within Postgres proper, given that
you're not seeing a performance problem with local connections.

Another thing you might try just to obtain more data is to test local
connections that use TCP rather than Unix-socket transport, eg
    psql -h 127.0.0.1

> I use IP authentification (no username/password).

You mean "trust"?  Please describe your pg_hba contents *exactly*;
this might be a relevant difference ...

            regards, tom lane



Re: Slow Remote connection

From
Jean-Arthur Silve
Date:
Well...

I tried to connect with psql -h 127.0.0.1 mydb and it's slow (+/- 5 sec.)
and psql mydb is fast ( less than 1 sec.) !

Here is my pg_hba :


.. few comments...
local      all                                          trust
host       all         127.0.0.1     255.255.255.255    trust
host       all         my_ip 255.255.255.255 trust


where my_ip is an IP address

May be I have a probleme with my system ?
version of the kernel is 2.4


jean-arthur




At 18:55 24/06/02 -0400, Tom Lane wrote:
>Jean-Arthur Silve <jeanarthur@eurovox.fr> writes:
> > I have a httpd server on one server, and PostgresQL 7.2 on a second server
> > (P4 1.7 Ghz / Linux ) on a local network.
>
> > When there are about 20 (and more ) connection on the DB, the remote
> > connecxtion to the DB from the web server is very long (about 5-10 sec)
> > before have the prompt.
>
> > On the local machine, it's near immediate.
>
>Weird.  Perhaps something wrong with your DNS setup, causing it to take
>a long time to resolve the name of the other machine?  Anyway I'd
>suspect that the problem is not within Postgres proper, given that
>you're not seeing a performance problem with local connections.
>
>Another thing you might try just to obtain more data is to test local
>connections that use TCP rather than Unix-socket transport, eg
>         psql -h 127.0.0.1
>
> > I use IP authentification (no username/password).
>
>You mean "trust"?  Please describe your pg_hba contents *exactly*;
>this might be a relevant difference ...
>
>                         regards, tom lane




Re: Slow Remote connection

From
Tom Lane
Date:
Jean-Arthur Silve <jeanarthur@eurovox.fr> writes:
> I tried to connect with psql -h 127.0.0.1 mydb and it's slow (+/- 5 sec.)
> and psql mydb is fast ( less than 1 sec.) !

> Here is my pg_hba :
> local      all                                          trust
> host       all         127.0.0.1     255.255.255.255    trust
> host       all         my_ip 255.255.255.255 trust

Weird.  You're using trust in both cases, so there's no reason for
authentication to make any difference.

The only thing I can think of is that something is wrong with DNS name
resolution.  Do you have hostname_lookup enabled in postgresql.conf?
Does changing it to the other setting make any difference?  (Don't
forget to SIGHUP the postmaster after changing postgresql.conf, else
it won't notice.)

            regards, tom lane