This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
In my design I have multiple instances of Data, each of which uses a RandomAccessFile to read the database file. It seems to me that using RandomAccessFile mode "rws" (or "rwd") rather than "rw" will greatly simplify concurrent file access, when there are multiple instances of RandomAccessFile writing to the same file, because a client knows that as soon as a file-updating method has returned, other clients will be able to see the changes. But the consensus in this thread seems to be that "rw" is sufficient, can someone explain why?