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 data warehouses and data marts are to perform analytical processing or OLAP

The insights into organizational information that can be gained from analytical processing are instrumental in setting strategic directions and goals

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

Databases contain information in a series of two-dimensional tables, which means that you can only ever view two dimensions of information at one time.  In a data warehouse and data mart, information is multidimensional, it contains layers of columns and rows.  Each layer in a data warehouse or data mart represents information according to an additional dimension. Dimensions could include such things as products, promotions, stores, category, region, stock price, date, time, and even the weather.  The ability to look at information from different dimensions can add tremendous business insight.

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

An organization must maintain high-quality information in the data warehouse

Information cleansing and scrubbing is a process that weeds out and fixes or discards inconsistent, incorrect, or incomplete information

Without high-quality information the organization will be unable to make good business decisions

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

Many of the tool vendors who sell their products or software call it business Intelligence software rather than Data warehousing software. so what is it? 

Business Intelligence is a term commonly associated with data warehousing. Business Intelligence is a generalized term where a company initiates various activities to gather today's market information which also includes about their competitor. Today's business Intelligence systems are contrasted to more classical way of information gathering in mining and crunching the data in the most optimal manner. In short we can say BI simplifies information discovery and analysis. 

In this way the company will have a competitive advantage of business and intelligently using the available data in strategic and effective decision making. it has the ability to bring disparate data under one roof  with a meaningful information and ready for analysis.

so what has Data warehousing to do with Business Intelligence?

Business intelligence usually refers to the information that is available for the enterprise to make decisions on. A data warehousing (or data mart) system is the backed  or the infrastructural, component for achieving business intelligence. Business intelligence also includes the insight gained from doing data mining analysis, as well as unstructured data.

Example, data warehousing. All the source data from disparate sources are used to load/Stage data. Different sources can be flat files, another database or some other process. The starting point of the Data warehouse should extract the data in order to load into its environment.This is extracting. This data may not be the expected format or size. your business demands are different or your organization business requirements are different. So the business process has to modify the data or better word is to transform the incoming data to meet requirements and objectives. This is called Transformation. 

Once every slicing and dicing of the data is done along with applied business rules, this data is ready for loading into the target tables. This process is called Loading. So overall till now we have done Extraction, Transformation and Loading. In short we call this ETL. There are lot of tools available in today's market which does help in achieving the ETL process. Once this data is loaded in to the database, this is ready for next processing. We call that database as Data warehouse database. 

The next process could be building of data marts or directly reporting from it. There are lot of tools or software available for reporting/analysis. Some call it business reporting or analysis tool. But if you see the whole process has intelligence involved in business. we can call this or the gurus call it Data warehousing and the system involved from end to end is called business intelligence system.