I must say I'm really happy with MySQL, a SQL server released under the GPL. I recently had to combined around sixty (60) MS Access 97 databases containing the same 3 tables defs. Each database was running around 80-150 MBytes in size. I wrote some VBA code that would attach to each MDB file and run 3 append queries that would push the data into 3 tables on MySQL. After I was finished, the largest table had a little over 30 million records. Once again, I'm impressed with MySQL.

-Chris