What is the Difference Between Slice and Dice in Data Warehouse

The main difference between slice and dice in data warehouse is that the slice is an operation that selects one specific dimension from a given data cube and provides a new subcube while the dice is an operation that selects two or more dimensions from a given data cube and provides a new subcube.

A data warehouse is a system used for reporting and data analysis, which support decision making. Firstly, the data from multiple sources is extracted, transformed and loaded into the warehouse. Then, analytics is performed using Online Analytical Processing Server (OLAP), which is based on the multidimensional data model. There are various OLAP operations such as roll up, drill down, slice and dice, and, pivot (rotate). Roll up is used to aggregate on a data cube; drill down is used to reverse the operation of roll up while pivot is used to rotate the data axes in view in order to provide an alternative presentation of data. In this article, we are looking at slice and dice.

Key Areas Covered

1. What is Slice in Data Warehouse
     – Definition, Functionality, Usage
2. What is Dice in Data Warehouse
     – Definition, Functionality, Usage
3. What is the Difference Between Slice and Dice in Data Warehouse
     – Comparison of Key Differences

Key Terms

Data warehouse, Dice, OLAP, Slice

What is Slice in Data Warehouse

An OLAP cube is a multi-dimensional array of data.  Data as a cube with hierarchical dimensions help analyzing. The aligned data is easier to visualize and improves productivity.

Figure 1: OLAP slicing

Slicing selects a single value for one of its dimensions and builds a subset of the cube. According to the above diagram, the sales regions, products in the year 2005 and 2006 are sliced out of the data cube.

What is Dice in Data Warehouse

Dice selects specific values of multiple dimensions to produce a new subcube. An example is as follows.

Figure 2: OLAP Dicing

According to the above diagram, the sales figures for a limited number of product categories, time and region dimensions covering the original range are used to form the new cube.

Difference Between Slice and Dice in Data Warehouse

Definition

Slice is the act of picking a rectangular subset of a cube by choosing a single value for one of its dimensions, creating a new cube with fewer dimensions. Dice is the act of producing a subcube by allowing the analyst to pick specific values of multiple dimensions. Thus, this describes the main difference between slice and dice in data warehouse.

Usage

Another difference between slice and dice in data warehouse is their usage. Slice is used to select one particular dimension from a given cube and to provide a new subcube. Dice is used to select two or more dimensions from a given cube and to provide a new subcube.

Conclusion

Slice and dice are two operations that are used in OLAP strategy in data warehouses. The main difference between slice and dice in data warehouse is that the slice is an operation that selects one specific dimension from a give data cube and provides a new subcube while the dice is an operation that selects two or more dimensions from a given data cube and provides a new subcube.

Reference:

1. “OLAP Cube.” Wikipedia, Wikimedia Foundation, 24 Sept. 2018, Available here.
2. “Data Warehousing OLAP.” Www.tutorialspoint.com, Tutorials Point, Available here.

Image Courtesy:

1. “OLAP slicing” By Infopedian – Own work (CC BY-SA 3.0) via Commons Wikimedia [Translated]2. “OLAP dicing” By Infopedian – Own work (CC BY-SA 3.0) via Commons Wikimedia [Translated]