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伟大导师TOM教导我们说:
The EAV model works in one place: storing attributes of a single object, in the context ONLY of that object.
http://asktom.oracle.com/pls/ask ... 2314483800346542969
这个医学研究项目恰好满足这个条件:
In the case of clinical parameters, it is very rarely that one has to worry about referential integrity between parameters, because individual parameters are not related to each other: they are only related to a clinical event (and therefore, to a patient and a study).
假如他想从一群病人中找出符合某些条件的,那就会有一大堆行转列,对于效率来说简直是灾难。 |
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