From the Hacker's Guide about Sys(3) and Sys(2015): "two workstations calling one of these functions at the same time will get the same value. They're not suited to generating unique IDs"

I would rather suggest using a GUID as a primary key (see message #754540).

HTH

>Can anybody certify that the SYS(2015) function is generating unique ID. I plan to use this as a primary key in a big system and I want to be sure it won't generate duplicate...