I'm looking into rewriting Tectonicus' cache handling, which currently uses about a gazillion flat files. This works but it's pretty rough on the HDD both in terms of access and number of files/directories.
I'm interested in moving to some kind of DB backend, but last time I tried using a proper DB via Java I got bogged down in configuring JDBC sources and a whole load of enterprise-y wank that I didn't want or need, and most actual users would run as soon as they saw they had to do it.
Basically I want a file backed database which requires zero configuration on the user's part and preferably is written in pure java. Sql support is optional, I just need to be able to store and manipulate data sets too big to hold in memory. HyperSQL is the only thing I've found so far ( http://hsqldb.org/
). Can anyone recommend any others?