I am holding byte blocks (of, e.g., 16 bytes) in a large byte
 array (of n·16 bytes) sorted with respect to those blocks.
 I also have another unsorted byte array of »recent additions«.
 It is anticipated that often it has to be determined whether a
 certain block is contained in any of those two arrays.
 I.e., both blocks together implement a »set of byte blocks«.

 Eventually, the recent additions will be sorted and then both
 arrays will be written out to a file. The file is to contain
 the byte blocks of both arrays in a sorted order, so the next
 byte block written is chosen from both arrays to be the
 smallest left.

 I assume that I could implement the file access via either
 java.io or java.nio. So, what should I choose?

 In the web I read, that »NIO will be particularly relevant for
 developers of high-performance applications such as database
 engines«. My pair of arrays might be considered to be a kind
 of »database engine«. But still I do not know whether
 java.nio will have any benefits in my case.