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Message Posted: Wed, 22 Oct 2003 @ 20:14:16 GMT





     
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Subj:   Re: Question on 'sample'
 
From:   Dieter Noeth



TeradataForum wrote:

  When I do a 'sample' in a query, does this save on spool space or does the server build the entire set in the spool and then return the specified 'sample' ?  


  e.g.  


  select * from table
sample 100
 



Just run explain, it will tell you when the sample is created: If there's no WHERE-condition and no JOIN it's building only a spool of the sampled data, else it's spooling first and then doing the sample.


Dieter





     
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