Home Page for the TeradataForum
 
https:

Archives of the TeradataForum

Message Posted: Wed, 06 Jun 2007 @ 09:27:00 GMT


     
  <Prev Next>   <<First <Prev Next> Last>>  


Subj:   Re: Minimal Stats Sampling and a well-informed
 
From:   Geoffrey Rommel

  The number of distinct values will end up being extrapolated upwards, depending on the percentage of rows sampled. If 2% of the rows were sampled, then you could expect to see about 50 times more distinct values in the produced estimate....  


Carrie, this seems odd to me. Two percent is a large sample -- far more than is needed for a 99% confidence level. Why doesn't the sampler simply accept what it finds? Is it because of a fear that the sample isn't "truly random"?



     
  <Prev Next>   <<First <Prev Next> Last>>  
 
 
 
 
 
 
 
 
  
  Top Home Privacy Feedback  
 
 
Copyright for the TeradataForum (TDATA-L), Manta BlueSky    
Copyright 2016 - All Rights Reserved    
Last Modified: 28 Jun 2020