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Message Posted: Thu, 25 Jan 2001 @ 09:06:05 GMT


     
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Subj:   Re: FastLoad: Discarding Duplicate Rows
 
From:   John Dubery

We would like FastLoad to load duplicates optionally. Also with the option off we would want the duplicates written to an error table.

That wish is in response to the practical needs of a data warehouse. I think warehousing use of an RDBMS has a unique need for a combination of relational theory and practicality. The practicality requirement exists mainly because we're always dealing with someone else's data, i.e. data already accepted by operational systems as valid (however mistakenly!).

Relational theory is what we want to exert when we create data objects in our warehouse or mart. Hence we want to be able to enforce uniqueness for modelled tables.

On the other hand Teradata, like other RDBMSs, runs much faster on multisets. So we often resort to them but only from the place in the job flow where we've enforced uniqueness.


Regards,

John



     
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