groups_dbi($dsn, $user, $password, $sql)

With this function you can read groups from DBI source. Example:

 groups_dbi( 'DBI:mysql:rex;host=db01',
   user             => 'username',
   password         => 'password',
   sql              => "SELECT * FROM HOST",
   create_all_group => TRUE);

Database sample for MySQL

 CREATE TABLE IF NOT EXISTS `HOST` (
   `ID` int(11) NOT NULL,
   `GROUP` varchar(255) DEFAULT NULL,
   `HOST` varchar(255) NOT NULL,
   PRIMARY KEY (`ID`)
 );

Data sample for MySQL

 INSERT INTO `HOST` (`ID`, `GROUP`, `HOST`) VALUES
   (1, 'db', 'db01'),
   (2, 'db', 'db02'),
   (3, 'was', 'was01'),
   (4, 'was', 'was02');