Could anybody please let me know how to re-schedule the job:
The job was initially set up by a user who has left, so i'm trying to re-schedule.
I have re-scheduled the job : -
SAP_COLLECTOR_FOR_NONE_R3_STAT, which manages the above, but it doesn't create the SAP_REORG_NONE_R3_STAT_DB job as I was expecting.
You could use SM36->Standard Jobs to define the characteristics of the job (i.e. name, ABAP, default variant, frequency) and then re-schedule it from there. If you ever lose the released version of the job again, you would simply go into SM36->Standard Jobs and re-schedule it again.
SAP_REORG_NONE_R3_STAT_DB has a very simple definition - it executes ABAP RSN3_AGGR_REORG on a daily basis. This would be easy to define in SM36->Standard Jobs and make scheduling it easy.
We use SM36->Standard Jobs to define all our housekeeping jobs and then schedule them from there.