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  2. MIDRANGE-L
  3. June 2017

Re: Is it inefficient to have two unique keys where the second is redundant?

"MIDRANGE-L" <midrange-l-bounces@xxxxxxxxxxxx> wrote on 06/14/2017
02:28:13 PM:
There may be a business reason for the two unique keys. If only one
fields is unique, duplicates of the other field could be introduced into

the file, and there may be a business reason that shouldn't happen.

But if that scenario were true, then constraints other than those
described by the OP would be required. Meaning: The constraints
described by the OP won't prevent the scenario you described. To prevent
the scenario you described, the two constraints would have to omit the
second column.


Sincerely,

Dave Clark

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