This is a technique that applies a groupingofdata on specified elements common to two data sources and then evaluates additional data elements for a level of commonality or distinctness.
这种技术在两个数据源公共的指定元素上对数据进行分组，然后估计其他数据元素的相同程度或差异程度。
2
These capabilities include sorting, grouping, aggregating, and a large set of functions to manipulate the different data types.
这些功能包括排序、分组、聚集以及一个操作不同数据类型的大型函数集。
3
Multiple slices ofdata can be returned in a single query by using grouping sets or super-groups (such as ROLLUP) in the GROUP-BY clause of the SQL statement.