An apparatus, a computer program and a method for prefetching a predetermined number of data items to a cache. The method comprises obtaining a list of candidate data items and associated scores thereof, that comprises more candidate data items than the predetermined number of data items to be prefetched to the cache. The method comprises repeatedly selecting, based on scores of the candidate data items, a candidate data item from the list and determining whether to add the candidate data item to the cache. Determining whether to add the candidate data item to the cache comprises determining whether the candidate data item is retained by the cache; and in response to determining that the candidate data item is not retained by the cache, adding the candidate data item thereto. The repeatedly selecting and determining are performed until the predetermined number of data items is added to the cache.