(PHP 4 <= 4.1.0, PECL dbplus >= 0.9)
dbplus_prev — Get previous tuple from relation
$relation
   , array &$tuple
   )
   Reads the data for the previous tuple for the given
   relation, makes it the current tuple and will pass
   it back as an associative array in tuple.
  
   Returns DBPLUS_ERR_NOERR on success or a db++ error
   code on failure. 
  
This function is EXPERIMENTAL. The behaviour of this function, its name, and surrounding documentation may change without notice in a future release of PHP. This function should be used at your own risk.