postgresql/contrib/dblink/doc/connection
Joe Conway 809b38ce27 Restrict non-superusers to password authenticated connections
to prevent possible escalation of privilege. Provide new SECURITY
DEFINER functions with old behavior, but initially REVOKE ALL
from public for these functions. Per list discussion and design
proposed by Tom Lane.
2007-07-09 01:32:30 +00:00

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$PostgreSQL: pgsql/contrib/dblink/doc/connection,v 1.4.2.1 2007/07/09 01:32:30 joe Exp $
==================================================================
Name
dblink_connect -- Opens a persistent connection to a remote database
Synopsis
dblink_connect(text connstr)
dblink_connect(text connname, text connstr)
Inputs
connname
if 2 arguments are given, the first is used as a name for a persistent
connection
connstr
standard libpq format connection string,
e.g. "hostaddr=127.0.0.1 port=5432 dbname=mydb user=postgres password=mypasswd"
if only one argument is given, the connection is unnamed; only one unnamed
connection can exist at a time
Outputs
Returns status = "OK"
Notes
Only superusers may use dblink_connect to create non-password
authenticated connections. If non-superusers need this capability,
use dblink_connect_u instead.
Example usage
select dblink_connect('dbname=postgres');
dblink_connect
----------------
OK
(1 row)
select dblink_connect('myconn','dbname=postgres');
dblink_connect
----------------
OK
(1 row)
==================================================================
Name
dblink_connect_u -- Opens a persistent connection to a remote database
Synopsis
dblink_connect_u(text connstr)
dblink_connect_u(text connname, text connstr)
Inputs
connname
if 2 arguments are given, the first is used as a name for a persistent
connection
connstr
standard libpq format connection string,
e.g. "hostaddr=127.0.0.1 port=5432 dbname=mydb user=postgres password=mypasswd"
if only one argument is given, the connection is unnamed; only one unnamed
connection can exist at a time
Outputs
Returns status = "OK"
Notes
With dblink_connect_u, a non-superuser may connect to any database server
using any authentication method. If the authentication method specified
for a particular user does not require a password, impersonation and
therefore escalation of privileges may occur. For this reason,
dblink_connect_u is initially installed with all privileges revoked from
public. Privilege to these functions should be granted with care.
Example usage
==================================================================
Name
dblink_disconnect -- Closes a persistent connection to a remote database
Synopsis
dblink_disconnect()
dblink_disconnect(text connname)
Inputs
connname
if an argument is given, it is used as a name for a persistent
connection to close; otherwiase the unnamed connection is closed
Outputs
Returns status = "OK"
Example usage
test=# select dblink_disconnect();
dblink_disconnect
-------------------
OK
(1 row)
select dblink_disconnect('myconn');
dblink_disconnect
-------------------
OK
(1 row)