>I never get a duplicate ID, because I lock the system table record while I get the next one. Even in the event of an update failure to the system table, they will just get an error when adding the record with the duplicate ID. And then I have an update routine which determines the next ID for all the tables. So if they get an error that way, they will just have to run the update procedure..
>
>I really worry you will get a duplicate key problem pretty regularly if you have many users doing the same thing, like adding transactions. Sure, a milisecond isn't long, but it's long enough.
>
>Adam


Never had a dupe with SYS(2015) but I know that it's quite possible.

I have had problems with sequential primary keys generated from an outside table in some NT and Win95 peer-to-peer installations, I think maybe due to the fact that Windows can lie to the app and say something is written while still stuck in buffer, meanwhile other user has already flushed and written.