Ok, I want to make a program that requires a database.  But it only requires a 
local database that can reside in a single file.  It doesn't have to be 
relational or anything.  So just about every SQL database is overkill for this 
application.  I thought about something like berkdb and I found ruby-bdb, but it 
is documented poorly and I can't figure out how to use it.  I basically need a 
flat record table which I can query.  I would use csv, but that is actually 
slightly underpowered.

Can someone make a good suggestion for a database to use and also point to 
documentation on how to create ruby applications with that database?  Thanks.