History of Data Warehouse
- The data warehouse provided the ability to support decision making without disrupting the day-to-day operations, because:
- Operational information is mainly current – does not include the history for better decision making
- Issue of quality information
- Without information history, it is difficult to tell how and why things change over time
Data Warehouse Fundamentals
- Data warehouse – a logical collection of information – gathered from many different operational databases – that supports business analysis activities and decision-making tasks
- The primary purpose of a data warehouse is to combined information throughout an organization into a single repository for decision-making purposes – data warehouse support only analytical processing
- Data warehouse models
- Multidimensional Analysis and Data Mining - relational Database contain information in a series of two-dimensional tables
- In a data warehouse and data mart, information is multidimensional, it contains layers of columns and rows
- Dimension – a particular attribute of information
- Cube – common term for the representation of multidimensional information
- Once a cube of information is created, users can begin to slice and dice the cube to drill down into the information
- Users can analyse information in a number of different ways and with number of different dimensions
Multidimensional Analysis and Data Mining
- Data mining – the process of analysing data to extract information not offered by the raw data alone. Also known as "knowledge discovery" – computer-assisted tools and techniques for sifting through and analysing vast data stores in order to find trends, patterns, and correlations that can guide decision making and increase understanding
- To perform data mining users need data-mining tools
- Data-mining tool – uses a variety of techniques to find patterns and relationships in large volumes of information. Examples: retailers can use knowledge of these patterns to improve the placement of items in the layout of a mail-order catalogue page or Web page
- An organization must maintain high-quality data in the data warehouse
- Information cleansing or scrubbing – a process that weeds out and fixes or discards inconsistent, incorrect, or incomplete information
- Occur during ETL process and second on the information once if is in the data warehouse
- Contact information in an operational system
- Standardizing Customer name from Operational Systems
- Information cleansing activities
- Accurate and complete information
Business Intelligence
- Business intelligence – refers to applications and technologies that are used to gather, provide access, analyze data, and information to support decision making effort
- these systems will illustrate business intelligence in the areas of customer profiling, customer support, market research, market segmentation, product profitability, statistical analysis, and inventory and distribution analysis to name a few
- Eg: Excel, Access