Home Page for the TeradataForum
 

Archives of the TeradataForum

Message Posted: Fri, 12 Nov 2004 @ 09:44:54 GMT


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


Subj:   Re: Fieldstatistics vs lastaltertimestamp in TVFields
 
From:   Dieter Noeth

  Would someone be able to explain to me the difference (or more so FieldStatistics) between the LastAlterTimestamp column verse the FieldStatistics column in DBC.TVFields?  


  I understand that FieldStatistics holds the index and column histograms. Inside the field is the (and I quote from Teradata RDBMS SQL Reference manual) "Time the statistics were collected." I have written SQL to extract this date but when compared to the LastAlterTimestamp date there is a big difference. It appears that the LastAlterTimestamp is actually holding the correct date as to when the last time we collected statistics on a particular column. It also appears that the LastAlterTimestamp date is the same as the date when doing a Statistics command in Teradata Administrator. So what date is kept with in the FieldStatistics column?  


Interesting...

I never noticed that before :-(

But it's easy to explain ;-)

     LastAlterTimestamp -> Start time of Collect Stats
     FieldStatistics -> Time when FieldStats where updated

So, if it's a Collect Stats on a single column, the difference is the time needed to collect those stats...


Dieter



     
  <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: 15 Jun 2023