I am working on an application that is going to run a tomcat front end and an embedded derby db back end. i need to devise a unique record identifier so i can easily import, export, and backup the db.

I don't think incremented id fields area good idea since there could be a lot of backing up, restoring, and possible merging of data.

would a good unique record id be something like ...
YYYYMMDDHHmmSSMLS

mm being minute.
MSL being millisecond.

I could create a unique field flag on the id column to make sure the ids for the table are unique. Does anyone see a problem with this?

I have done a ton of research but for this particular application I could not find a good solution. I need a unique record id that is flexible and generated by my program.

Of course there is also GUIDs.