CHAPTER 8 : ACCESSING ORGANIZATIONAL INFORMATION - DATA WAREHOUSE

1. Describe the roles and purposes of data warehouses and data marts in an organization 

The primary purpose of a data warehouse is to aggregate information throughout an organization into a single repository for decision-making purposes. Data warehouse is gathered from many different operational databases. It also supports business analysis activities and decision-making tasks. Data marts are contains a subset of data warehouse information. On the other hand, data mart is a decision support system incorporating a subset of the enterprise's data focused on specific functions or activities of the enterprises. 

2. Compare the multidimensional nature of data warehouses (and data marts) with the two-dimensional nature of databases 

Databases contains information in a series of two-dimensional tables. Most databases contain multiple tables, which may each include several different fields. For example, a company database may include tables for products, employees, and financial records. Each of these tables would have different fields that are relevant to the information stored in the tables. In a data warehouse and data mart, information is multidimensional which is contains layers of columns and rows. Each layer in these data represents information according to the additional dimension. It includes products, promotions, category, stores, date and any else that related. 

3. Identify the importance of ensuring the cleanliness of information throughout an organization

An organization must maintain high-quality in the data warehouse. Information cleansing and scrubbing is a process that weeds out and fixes or discards inconsistent, incorrect, or incomplete information. The organization will be unable to make good business decision without high-quality information.  

4. Explain the relationship between business intelligence and a data warehouse

Business intelligence is an information that people use to support their decision-making efforts. A data warehouse is an enabler of business intelligence. The purpose of data warehouse is to pull all kinds of disparate information into a single location where it is cleansed and scrubbed for analysis.