Statistics Threshold Functionality 101 - comment by carrie

Laeeq,
 
The default settings are all zeros, your information below is correct.   The first two parameters are described above in the blog posting under the heading. 
                More about DBA-Defined Global Thresholds
They are turned off by default, and should stay off for most sites.  They are useful if the site has its own stats management application and wants to replace the global threshold setting (setting #3) with their own customized thresholds.
 
The other two settings generally should stay on by default, unless you have a specific reason to turn off the global threshold feature, or the automatic downgrade to sampling feature.  
 
So, basically you do not need to modify these parameters, unless for some reason you do not want the default behavior.  See the orange book Teradata database 14.10 Statistics Enhancements page 40 and 41 for a fuller explanation of these options.  
 
I'm not sure this is what you intended to say, but those statistics parameters do not give the system the power to determine when to collect stats.  You still have to issue collect statistics statements, or if you are using the Stats Manager portlet, then Viewpoint needs to submit the statements.  The 3rd setting, SysChangeThresholdOption, gives the optimizer the ability to NOT collect statistics (to skip collections) once the collection statements have been submitted to the database, based on internally determined thresholds being reached or not being reached.
 
Thanks, -Carrie