This function is EXPERIMENTAL. The behaviour of this function, the name of this function, and anything else documented about this function may change in a future release of PHP without notice. Be warned and use this function at your own risk.
dbplus_flush() will write all changes applied to relation since the last flush to disk.
The function will return zero (aka. DBPLUS_ERR_NOERR) on success or a db++ error code on failure. See dbplus_errcode() or the introduction to this chapter for more information on db++ error codes.