简单十步让你全面理解SQL-云栖社区 ... IN往往比EXISTS更具可读性 ANTI JOIN(反连接) CROSS S JOIN(交叉连接) ...
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反馈连接 feedback ; [自] feedback connection
反极性连接 reversed polarity
反向连接 Reverse Connection ; [计] backward link ; inverted connection ; backward connection
连接反应 ligation ; ligation reaction
极性相反连接器 Reverse Polarity
无反射连接 reflexionless connection
反意连接词 disjunctive ; adversative conjunction
反馈系统连接 Feedback
正反面连接 feed-thru connection ; [计] frontback connection
这些变化意味着结果视图现在是不可合并的,也就是不用考虑半连接和反连接了。
These changes mean that the resultant view is now non-mergeable allowing semi or anti joins to be contemplated.
这意味着,虽然反模式中的任务 Task 4 的所有输入都已经连接了,但该任务仍然无法执行。
This means Task 4 in the anti-pattern cannot execute, although the task has all its inputs connected.
从理论上来说,总是建议您保证数据的规范化;但是在实践中,过度的规范化(或者没有恰当反规范化的规范化)会导致对数据检索连接的依赖性。
Data normalization is always recommended in theory, but in practice over-normalization (or normalization without appropriate de-normalization) lead to reliance on joins for data retrieval.
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