I've hunted around lately for exactly the same, and the best that I've come across is a set of PGN files located at:
http://chessnostalgia.com/PGNDownloads.html
Although they're not in a single file, it's pretty easy to either string them together into one big file and/or slurp them into your database tool of choice for consolidation.
Does anyone know a place where I can download a free pgn database? I've seen many sites for downloading individual games but not one for a whole database.
If you want a Java based database ------> http://www.chesslab.com/PositionSearch.html