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Message Posted: Wed, 09 Aug 2006 @ 16:35:50 GMT


     
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Subj:   Question concerning Statistics
 
From:   Ferry, Craig

I noticed something odd with help statistics that I was hoping someone could help me to clarify. I collect statistics on all columns and indices of tables after I load them nightly. One of the fields in one of the tables is called country_code.

If I run a SELECT country_code FROM my_table GROUP BY country_code, it returns two rows.

If I run a help statistics on my_table, it shows 101 unique values.

Any suggestions as to why this may be occurring?

Also, is there a rule of thumb as to when it may actually be detrimental to run statistics (or is it always good). For example, if your unique values are x percent of the total table rows.


Thanks

Craig

Craig Ferry
Manager, Data Warehousing and Central Systems
WESCO Distribution, Inc.



     
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