Home Page for the TeradataForum

Archives of the TeradataForum

Message Posted: Thu, 06 May 2004 @ 08:09:43 GMT

  <Prev Next>   <<First <Prev

Subj:   Re: Collect Stats on Indexes versus Multi-Column
From:   Victor Sokovin

On Wed, 5 May 2004 21:56:34 +0200, Dieter Noeth wrote:

  There's a difference:
You can drop and recreate that index without losing statistics (similar to a single column index), if you collect on multi-column, because those statistics are stored as a pseudo-index (with indextype 'M') in dbc.indexes.

I believe different algorithms for calculating the stats might be used as well. It is especially clear from the documentation if you take the part on sample stats. This might be the difference even in the single column case. I would keep experimenting with both syntax forms.

And the two statements you mentioned are surely not equivalent if TableA != TableB but I assume you were not testing our observation capacity.



  <Prev Next>   <<First <Prev
  Top Home Privacy Feedback  
Copyright for the TeradataForum (TDATA-L), Manta BlueSky    
Copyright 2016 - All Rights Reserved    
Last Modified: 15 Jun 2023