Statistics Collection Recommendations – Teradata 14.10, 15.0 and 15.10 - comment by carrie

Here is a link for an article here on Dev X that describes STATSUSAGE and XMLPLAN:
 
http://developer.teradata.com/database/articles/identifying-used-unused-and-missing-statistics
 
There is no way to turn off stats extrapolation.  However, extrapolation only takes place if statistics are stale.  Keeping stats up to date will eliminate the need for the optimizer to extrapolate.   Collecting summary stats frequently, even if you cannot collect full stats that often, will help ensure that extrapolations are more accurate.  If you think extrapolation is not working as it should, it would be advisable to open an incident with the support center.
 
Thanks, -Carrie