Introduction To Data Warehousing

A data warehouse is a type of computer database that is responsible for collecting and storing the information of a particular organization. The goal of using a data warehouse is to have an efficient way of managing information and analyzing data.
In addition to a relational database, a data warehouse environment includes an extraction, transportation, transformation, and loading (ETL) solution, an online analytical processing (OLAP) engine, client analysis tools, and other applications that manage the process of gathering data and delivering it to business users.

Despite the fact that data warehouses can be designed in a number of different ways, they all share a number of important concepts.
A data warehouse is a :
- Subject-oriented : This means that the information that is in the data warehouse is stored in a way that allows it to be connected to objects or events which occur in reality.
- Integrated : Data warehouses must put data from disparate sources into a consistent format. They must resolve such problems as naming conflicts and inconsistencies among units of measure. When they achieve this, they are said to be integrated.
- Time-variant : A time variant will allow changes in the information to be monitored and recorded over time.
- Non-volatile : This means that it cannot be deleted, and must be held to be analyzed in the future. All of the programs that are used by a particular institution will be stored in the data warehouse, and it will be integrated together.



CHARACTERISTICS OF DATA WAREHOUSES :
- Multi-dimensional conceptual view.
- Generic dimensionality.
- Unlimited dimensions and aggression levels.
- Unrestricted cross-dimensional operations.
- Dynamic sparse matrix handling.
- Client-server architecture.
- Multi-user support.
- Accessibility.
- Transparency.
- Intuitive data manipulation.
- Consistent reporting performance.
- Flexible reporting.