Þ B. BY DEFINITION, GROUP FUNCTIONS CAN OPERATE ON MULTIPLE ROWS AT...

2. þ B. By definition, group functions can operate on multiple rows at a time, unlike single-row functions.ý A, C, and D. A group function may be used without a GROUP BY clause. In this case, the entire dataset is operated on as a group. The COUNT function is often executed against an entire table, which behaves as one group. D is incorrect. Once a dataset has been partitioned into different groups, any group functions execute once per group.