Contents
What type of cube materialization does MultiWay array aggregation perform?
4. The Full cube • The multi way array aggregation method computes full data cube by using a multidimensional array as its basic data structure 1. Partition array into the chunks 2. Compute aggregate by visiting (i.e. accessing the values at) cube cells Advantage the queries run on the cube will be very fast.
What consolidates data in multidimensional space to form partially materialized data cubes?
A data warehouse integrates data originating from multiple sources and various timeframes. It consolidates data in multidimensional space to form partially materialized data cubes.
How computations can be performed efficiently on data cubes?
Efficient methods for data cube computation methods are: A. the multiway array aggregation (MultiWay) method for computing full cubes. a method known as BUC, which computes iceberg cubes from the apex cuboid downward.
What is cube computation?
Data cube computation is an essential task in data warehouse implementation. The precomputation of all or part of a data cube can greatly reduce the response time and enhance the performance of online analytical processing.
What is multi-way Array Aggregation for cube computation?
The Multiway Array Aggregation (or simply MultiWay) method computes a full data cube by using a multidimensional array as its basic data structure. It is a typical MOLAP approach that uses direct array addressing, where dimension values are accessed via the position or index of their corresponding array locations.
What is Star-cubing?
The Star-Cubing algorithm explores both the top- down and bottom-up models: On the global computa- tion order, it uses the top-down model similar to Fig- ure 1. However, it has a sub-layer underneath based on the bottom-up model by exploring the notion of shared dimension.
What is Star cubing?
Why data cube computation is needed?
Data cube computation is an essential task in data warehouse implementation. The precomputation of all or part of a data cube can greatly reduce the response time and enhance the performance of on-line analytical processing.
What is an iceberg cube?
An Iceberg-Cube contains only those cells of the data cube that meet an aggregate condition. It is called an Iceberg-Cube because it contains only some of the cells of the full cube, like the tip of an iceberg. The aggregate condition could be, for example, minimum support or a lower bound on average, min or max.
How does drill down operation affect the size of data cube?
Drill-down occurs by descending the time hierarchy from the level of week to the more detailed level of day. Also new dimensions can be added to the cube, because drill-down adds more detail to the given data. Slice performs a selection on one dimension of the given cube, thus resulting in a subcube.