Efficient computation of aggregations plays important role in data warehouse systems. Multidimensional data analysis applications aggregate data across many dimensions looking for anomalies or unusual patterns. The SQL aggregate functions and the GROUP BY operator are used for aggregation. But data analysis applications need the N-dimensional generalization of these operators. Data cube is introduced which is a way of structuring data in N-dimensions so as to perform analysis over some measure of interest. Data cube computation is essential task in data warehouse implementation.