> this possible). So worst case scenario I'd say, temp would need to be > as large as your largest segment. Hi Rich, I notice that you are using a combination of parallel => 2, and the method_opt=> FOR ALL COLUMNS SIZE AUTO. This basically means that you *may* be running two threads that might select, sort and count (in TEMP) multiple columns to determine histograms. If one thread analyzing your largest segment occupies all the TEMP area, you may still need some more for the histogram calculations (along with other active TEMP users at that time). I would give it a 1.5 times your largest segment just to be sure. -- John Kanagaraj <>< http://www.linkedin.com/in/johnkanagaraj http://jkanagaraj.wordpress.com (Sorry - not an Oracle blog!) ** The opinions and facts contained in this message are entirely mine and do not reflect those of my employer or customers ** -- //www.freelists.org/webpage/oracle-l