Interview Questions
1. Explain rollup? Ans. ROLLUP processes groups of input records that have the same key, generating one output record for each group. Typically, the output record summarizes or aggregates the data in some way; for example, a simple ROLLUP might calculate a sum or average of one or more input fields. ROLLUP can select certain information from each group; for example, it might output the largest value in a field, or accumulate a vector of values that conform to specific criteria. Two modes to use ROLLUP You can use a ROLLUP component in two modes, depending on how you define the transform parameter: Template mode — You define a simple rollup function that may include aggregation functions. Template mode is the most common way to use ROLLUP . Expanded mode — You create a transform using an expanded rollup package. This mode allows for rollups that do not necessarily use regular aggregation functions. 2. How to ac...