The relational database model introduced a programming-language independentStructured Query Language (SQL), based onrelational algebra.
The terms "data" and "information" are not synonymous. Anything stored is data, but it only becomes information when it is organised and presented meaningfully.Most of the world's digital data is unstructured, and stored in a variety of different physical formatseven within a single organization. Data warehouses began to be developed in the 1980s to integrate these disparate stores. They typically contain data extracted from various sources, including external sources such as the Internet, organised in such a way as to facilitate decision support systems (DSS).
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