This chapter is about assessing organization information by data warehouse. A data warehouse is a logical collection of information which is gathered from many different operational database. It supports business analysis activities and decision making tasks.
Data warehouse- A data warehouse is a collection of data, usually current and historical, from multiple databases that the organization can use for analysis and decision making. The purpose, of course, is to bring key sets of data about or used by the organization into one place.
Data mart- Data marts are related sets of data that are grouped together and separated out from the main body of data in the data warehouse.
The purpose of data warehouse is to aggregate information throughout an organization into a single repository in such way that employee can make decision and undertake business analysis activities.
besides that, database store all the transaction such as sales of product.
The roles of data mart is easily to employee to access the data information. Other than that, data marts as having focuses information subsets particular to the needs of a given business unit such as finance or production and operations.
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 (thus the need of content management systems). Let me give the path of 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 datamarts or directly reporting from it. There are lot of tools/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.