topic is &sysjobid unique? in SAS Programming

is &sysjobid unique?

mrzd — Tue, 02 Aug 2011 08:57:17 GMT

Hi!

We plan to use the &sysjobid macro variable as an id for our historical tables to indicate uniqueness of data batches. Is it possible to recur?

Thanks for the help!

is &sysjobid unique?

mrzd — Tue, 02 Aug 2011 08:58:40 GMT

by the way, we have a Unix envt. :smileylaugh:

is &sysjobid unique?

Peter_C — Tue, 02 Aug 2011 12:37:11 GMT

in SAS on unix the sysjobID is filled with the PID (the process ID) value. It will _very_ probably be unique. I cannot imagine how it would not be unique.

is &sysjobid unique?

Tom — Tue, 02 Aug 2011 13:34:21 GMT

I am not sure the &SYSJOBID will be unique over time so that you could use it as a historical reference. I know that on Unix it will restart the process id numbers when the server reboots. They might even cycle around if you run the server long enough. Also what if your jobs are distributed across servers.

is &sysjobid unique?

LinusH — Wed, 03 Aug 2011 07:49:13 GMT

Agree with Tom, the pid is not unique over time.

So you probably have to create your own id. Or, why not use a timestamp, that should be unique in most applications?

/Linus

is &sysjobid unique?

mojerry2 — Wed, 03 Aug 2011 12:28:35 GMT

Hi,

No, pid is certainly not unique otherwhise after a while your server can't run any process because the pid is full...

you could use a reference table who logs your id and each time you want to create a new one select max+1 and the jobname.

other possiblity is jobname+datetime.

date is not enough, you could run twice the same day your process. never say never...

is &sysjobid unique?

Peter_C — Wed, 03 Aug 2011 12:55:30 GMT

as we use more parallel processing like grid, we will increase the number of ways similar tasks might start at the same time.

However, a consistent hash of server address and timestamp and process id + perhaps a 6-digit random number, might generate a unique id

is &sysjobid unique?

Peter_C — Wed, 03 Aug 2011 12:59:45 GMT

so, guess the correct answer is:

is &sysjobid unique?

mrzd — Mon, 08 Aug 2011 05:20:43 GMT

I see. Thanks for the help guys, as well as for the tips.