boolean function ( ) { return false ; }
if it is possible to collect all clusterwide available keys for this keyvaluesource implementation then this method returns true . if true is returned , a call to #getallkeys must return all available keysto execute a preselection of interesting partitions / nodes based on returns keys . if this functionality is not available and job #onkeys object , job #onkeys iterable , or job #keypredicate keypredicate is used , apreselection of the interesting partitions / nodes is not available and the overall processing speed my be degraded . concode_field_sep PlaceHolder placeHolder concode_field_sep KeyValueSource<K,V> fromMap concode_elem_sep KeyValueSource<K,V> fromMultiMap concode_elem_sep KeyValueSource<String,V> fromList concode_elem_sep Collection<K> getAllKeys concode_elem_sep Collection<K> getAllKeys0 concode_elem_sep boolean reset concode_elem_sep boolean hasNext concode_elem_sep KeyValueSource<String,V> fromSet concode_elem_sep boolean open concode_elem_sep K key concode_elem_sep Map.Entry<K,V> element