For example, this might happen when two ore more of the tables in the MQT have a referential integrity relationship defined and the join predicate is on their primary key - foreign key columns.

例如，当MQT中的两个或多个表定义了引用完整性关系并且联结谓词在它们自己的主键-外键列上时，就会出现这种情况。

youdao

Whether and when this might happen, though, is uncertain.

会不会发生或者什么时候间发生，尽管这还不是很确定。

youdao

This might happen when it is desirable to centralize the enterprise models but necessary to maintain permanent variance in one or more divisions, business units or regions.

当需要集中企业模型而不需要维护一个或者多个部门、商业单位或者地区之间永久性的差异性时，这种情况就会出现。

youdao

We're not making any bets on when this might happen or if it ever will.

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Gabriele is "very likely" to be pardoned by Pope Benedict, Vatican spokesman Federico Lombardi said, though it is not clear when this might happen.

BBC: Pope ex-butler Paolo Gabriele jailed for theft

It made a nod towards business for example, with a promise to bring down corporate taxation but gave no sense of when this might realistically happen.

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