data warehousing

Question

what is data warehousing?

Answer 1

From Wikipedia:

A data warehouse is a repository of an organization's electronically stored data. Data warehouses are designed to facilitate reporting and analysis.

This 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 the data dictionary are also considered essential components of a data warehousing system. Many references to data warehousing use this broader context. Thus, an expanded definition for data warehousing includes business intelligence tools, tools to extract, transform, and load data into the repository, and tools to manage and retrieve metadata.

The advantage of data warehousing is it has functionalities to support data analysis, data mining and document reporting which can be computationally expensive if done on Database management servers.

More: http://en.wikipedia.org/wiki/Data_warehouse

Answer 2

Data Warehouses

• Store lots of data on a computer / set of computers in order to provide information
• Deal with statistics but not transactions

Creating a Warehouse

• Normally Data from many databases / data sources is combined and then copied as a snapshot
• The snapshot is never updated – but later snapshots are added

Putting it Together and Searching It

• Arranged in complicated multidimensional structure To produce graphs and statistics not
• single results and new knowledge is then extracted