Home Page for the TeradataForum
 

Archives of the TeradataForum

Message Posted: Mon, 11 Jul 2005 @ 09:31:52 GMT


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


Subj:   Optimizer and bind variables
 
From:   Anomy Anom

<-- Anonymously Posted: Monday, July 11, 2005 00:11 -->

Hi,

The TD optimizer genereates the plan without the knowledge of the bind variables. Then at the APPLY step, binds the variables with the values. -- Is this a correct understanding?

If so, how does the optimizer decide on plans when there is a data skew? Lets say theres a column with a NUSI. It is strongly selecetive for all values except for a specific value say X for which theres a spike. How can the optmizer take a decision to use the NUSI or go for an FTS without knowing what the value is?

The Oracle optmizer has a feature called "BIND PEEKING" which is specifically designed for this kind of scenarios.

Is my understanding of TD optmizer correct? Pls correct me if am wrong!


Thanks



     
  <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: 27 Dec 2016