Explain various features of Data Warehouse?
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Following are the features of Data Warehouse
- Subject-oriented
- Integrated
- Time-variant
- Nonvolatile
Subject-oriented :
- A data warehouse is organized around major subjects, such as customer, supplier, product, and sales
- Rather than concentrating on the day-to-day operations and transaction processing of an organization, a data warehouse focuses on the modeling and analysis of data for decision makers.
- Data warehouses typically provide a simple and concise view around particular subject issues by excluding data that are not useful in the decision support process
Integrated :
- A data warehouse is usually constructed by integrating multiple heterogeneous sources, such as relational databases, flat files, and on-line transaction records.
- Data cleaning and data integration techniques are applied to ensure consistency in naming conventions, encoding structures, attribute measures, and so on.
Time-variant :
- Data are stored to provide information from a historical perspective (e.g., the past 5–10 years).
- Every key structure in the data warehouse contains, either implicitly or explicitly, an element of time
Nonvolatile :
- A data warehouse is always a physically separate store of data transformed from the application data found in the operational environment.
- Due to this separation, a data warehouse does not require transaction processing, recovery, and concurrency control mechanisms