How to set the 'write mode' to rwd?

[Barnet Wagman]

I'm getting the "Failed to create database" error in OS X, and I've read 
that I need to set the write mode to rwd (the default is rws). 

Could someone tell me how to do this (or where it's documented)?  The 
only reference to the write modes that I've found is in the api doc of 
org.apache.derby.impl.io.DirRandomAccessFile.  I've never used this 
class (explicitly) and hopefully I won't have to.

Are there performance and/or reliability implications of switching to 
rwd?  I'd like to avoid having a separate version of my app for OS X - 
would using rwd on Linux and/or Windows be a bad idea?

Thanks

bw