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by kmeisthax 1060 days ago
Your log tables don't have timestamps or line numbers on them?

More generally (and formally) speaking, multisets violate normalization. Either you add information to the primary key to identify the copies or you roll the copies up into a quantity field. I can't think of any kind of data where neither of these would be good options.
1 comments
deely3 1060 days ago
Primary key and quantity field could be not a perfect solution from performance point of view. Timestamps does not guarantee uniqueness.

Look, Im not trying to win the argument. In most cases you definitely right, my point is that sometime you have to work with working legacy code/system, and sometime this system could have some unique features.

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Dylan16807 1060 days ago
It's still not something you "want to have", it's something you might be forced to deal with because someone screwed up the design.

And ensuring you have a real primary key should only be good for performance, in the realm of SQL databases.

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