See this testcase run on 11.2.0.3:
https://www.bobbydurrettdba.com/uploads/emptystats.zip
If you have a subpartitioned table – at least of the type that I tested – the Oracle delivered stats job will leave the statistics empty (NULL) for empty subpartitions instead of setting them to zero. If you manually gather statistics on the same table you will have zero stats on the empty subpartitions.
I can’t see any evidence of this causing a problem but it is disconcerting to see NULL stats when you are expecting the job to gather them.
– Bobby
