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Re: Merging two tables with primary keys
Posted by: Peter Brawley
Date: March 25, 2018 10:55AM

> Not sure what that means.

It means you now need to form and test rules for deciding which column values in two rows with identical PKs should be kept and which should be archived or discarded.

For example, in a DB that completely implements point-in-time architecture (http://www.artfulsoftware.com/infotree/Transaction%20time%20validity%20in%20MySQL.pdf), you would probably just pick the most recent value of each column.

To the extent your DB does not maintain such history, you will have to devise rules for choosing which column value to keep, and which to archive or discard.

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Re: Merging two tables with primary keys
March 25, 2018 10:55AM


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