ok thanks Flip......i am so noob. ... View more

Thanks a lot Milton, it work fine. Best Regards Message was edited by: Darth SAS ... View more

I heard a logical explanation for concern about use of "monotonic()". When an sql platform/optimiser/engine has enough information to multi-thread resolution of a query," monotonic()" may be implemented in parallel across threads. The result would not be what is desired. For simple platforms and queries, that can be expected to single-thread, monotonic() should be able provide the unique id. This scenario, where a feature cannot be expected to "universally" work, applies in other parts of SAS. For example the number of observations indicated by the NOBS= option on a SET statement, will be missing (or may even be negative) when the data set is a view or subject to a where clause. PeterC ... View more