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terasum 13 posts Joined 10/12
13 Jun 2013
Why can we have UPI only when PPI column is part of PI

Why can we have UPI only when PPI column is part of PI, can someone explain in detail?
 
Thanks in Advance

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terasum 13 posts Joined 10/12
10 Jul 2013

Any help is appreciated !!

CarlosAL 512 posts Joined 04/08
11 Jul 2013

If the column was not part of the PPI TD should check all and every partition to guarantee unicity, which has a high cost.
That's why. (it's in the manuals, BTW)
Cheers.
Carlos.

VBurmist 96 posts Joined 12/09
11 Jul 2013

Hi Terasum,
If you really want to check uniqueness in this case, then you can create a USI for the NUPI column(s) for the partitioned table.   This would use the USI index to reduce the high cost which Carlos has explained.
Regards,
Vlad.

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