DATA WAREHOUSING

A data warehouse is a repository of an organization’s electronically stored data. Data Warehouse are designed to facilitate reporting and analysis. This classic definition of the data warehouse focuses on data storage. However, the means to retrieve and analyze data, to extract, transform and load data, and to manage dictionary data are also considered essential components of a data warehousing system. An expanded definition of data warehousing includes business intelligence tools, tools to extract, transform, and load data into repository, and tools to manage and retrieve metadata.

Benefits of Data warehousing:

Some of the benefits that a data warehouse provides are as follows:

• A data warehouse provides a common data model for data, regardless of the data’s source. This makes it easier to report, analyze information than it would be if multiple data models from disparate sources were used to retrieve information such as sales invoices, order receipts, general ledger charges etc.

• Prior to loading of data into data warehouse inconsistencies are identified and resolved. This greatly simplifies reporting and analysis.

• Information in the data warehouse is under the control of data warehouse users so that, even if the source system data is purged over time, the information in the warehouse can be stored safely for extended periods of time.

• Because they are separate from operational systems, data warehouses provide fast retrieval of data without slowing down operational systems.

• Data warehouses facilitate decision support system applications such as trend reports (e.g. Items with the most sales in a particular area within the last two years), exception reports, and reports that show actual performance versus goals.

• Data warehouses can work in conjunction with and hence enhance the value of operational business applications, notably customer relationship management systems.