Returns a set of tuples from extracted dimension elements.

从析取的维度元素中返回元组集合.

Returns the number of tuples in a set, optionally including or excluding empty tuples.

返回某个集合中元组的数目, 可以包括或排除空元组.

As you see, on output tuples are always enclosed in parentheses, so that nested tuples are interpreted correctly;

如你所见，元组输出时总是用括号包裹的，这便于正确的表达嵌套元组。

The global associated shedding strategy considers tuples from all involving relations globally, and chooses evicted tuples from this global view.

全局关联卸载策略将所有参与连接的关系元组进行全局考虑，从中选择被卸载的数据元组。

You can also compare tuples in their entirety (see Listing 16).

还可以将元祖作为整体进行比较（参见 清单16）。

For example, tags in tuples can be used to select different operations (see Listing 33).

例如，可以使用元组中的标签选择不同的操作（参见 清单33）。

The order of tuples in the resulting set depends on the order of the sets to be joined and the order of their members.

所得集中元组的顺序取决于要联接的集的顺序以及其成员的顺序。