Serial Numbers

Hi all, A problem that I have been experiencing, and I am sure so have many others, is the use of serial numbers within transaction tables. The problem that I found is that the complete table is locked for inserts if a user inserts a record that contains a serial number for the duration of a transaction. Because serial numbers are typically used in transaction tables only one user can effectively insert a record in a transaction table at a time. It is, of course, possible to create a custom serial mechanism using a different table but again this would be locked up for the duration of the transaction. Is there anyone out there with an elegant solution to this problem? Note that if a number is lost it is not the end of the world. However, no number may be duplicated. Thanks Theo theo@rascal.co.za