Auto-Update Statistics versus Update Statistics - are they the same?
Posted on 2004-08-25
If I run update statistics (with a sample) it samples a "representative sample" of the data.
If I turn autoupdate statistics on, does that simply run "update statistics" when the threshholds (roughly 20% rows changed) are reached, OR, does it sample the changed data to determine how the stats should be modified.
The question is important because my client has been running with autostats OFF for some time, and the question is whether we should recalc statistics at 100% before turning autoupdate on.
I will award extra points if someone can tell me whether the 20% factor can be changed