Get information about the table and database name from the prefix.
A keyed array with information about the database, table name and prefix.
Overrides Schema::getPrefixInfo
protected function getPrefixInfo($table = 'default', $add_prefix = TRUE) {
  $info = array(
    'prefix' => $this->connection
      ->tablePrefix($table),
  );
  if ($add_prefix) {
    $table = $info['prefix'] . $table;
  }
  if (($pos = strpos($table, '.')) !== FALSE) {
    $info['database'] = substr($table, 0, $pos);
    $info['table'] = substr($table, ++$pos);
  }
  else {
    $db_info = Database::getConnectionInfo();
    $info['database'] = $db_info['default']['database'];
    $info['table'] = $table;
  }
  return $info;
}