Multiple instances adding to the same attribute.

Maybe you can use the optimistic locking. In rails, Optimistic locking is enabled by default on any table that contains an integer column called lock_version. Then, you can handler the exception yourself or just discard it depend to your project.

Michael,

Sorry about that. I got a bounce from the group and reposted it under
my other account. I misposted it to you.

Apoligies.