After viewing Jonathan Lewis' excellent presentation, ( http://www.speak-tech.com/lewis-20130610 ) the main thing
I got out of it was to set the 'approximate_ndv' to true and to avoid using histograms.
So, I checked my global preferences and confirmed they were set to the default values, specifically:
SNAME SPARE4
------------------- ----------------------------
APPROXIMATE_NDV FALSE
METHOD_OPT FOR ALL COLUMNS SIZE AUTO
So, by Jonathan's presentation, I will set APPROXIMATE_NDV to TRUE.
But my question is in regards to METHOD_OPT: Should I, (or would it be safe)
to set the global_prefs for this to "FOR ALL COLUMNS SIZE 1".
This would basically eliminate all histograms (eventually when it updates statistics), including any that Oracle uses on its own internal tables.