/**
  * Initialize the database with the according schema
  *
  * @param rcube_db $db Database connection
  *
  * @return boolen True on success, False on error
  */
 public function init_db($db)
 {
     $engine = $db->db_provider;
     // read schema file from /SQL/*
     $fname = INSTALL_PATH . "SQL/{$engine}.initial.sql";
     if ($sql = @file_get_contents($fname)) {
         $db->set_option('table_prefix', $this->config['db_prefix']);
         $db->exec_script($sql);
     } else {
         $this->fail('DB Schema', "Cannot read the schema file: {$fname}");
         return false;
     }
     if ($err = $this->get_error()) {
         $this->fail('DB Schema', "Error creating database schema: {$err}");
         return false;
     }
     return true;
 }