interface KeySelector<K>
ForwardCursor
.
The reason for implementing a selector, rather than filtering the objects
returned by the ForwardCursor
, is to improve performance when not
all keys are to be processed. Keys are passed to this interface without
retrieving record data or locking, so it is less expensive to return false
from this method than to retrieve the object from the cursor.
boolean selectKey(K key)
This method should not assume that the given key is for a committed record or not, nor should it assume that the key will be returned via the cursor if this method returns true. The record for this key will not be locked until this method returns. If, when the record is locked, the record is found to be uncommitted or deleted, the key will not be returned via the cursor.
Copyright (c) 2004-2012 Oracle. All rights reserved.