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 –
- The primary purpose of a data warehouse is to combined information throughout an organization into a single
- 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
- 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
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
Information Cleansing or Scrubbing
- 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,
- Occur during ETL process and second on the information once if is in the data warehouse
- Contact information in an operational system
- 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,
- these systems will illustrate business intelligence in the areas of customer profiling, customer support,
distribution analysis to name a few
- Eg: Excel, Access