What is the difference with the data warehouse database is it? Where each application scenarios in it?
For use in business systems database , which is usually stored online transaction data, based on business unit organization and storage of data. Because the database is for a particular application, the design method now commonly used relational model. By the relational model to ensure that data atomicity, consistency and integrity, eliminating data redundancy, the general rule in line with the paradigm to design constraints.
Data warehouse from the beginning of the design is to analyze data services, so the data is subject-oriented organizations to organize and store. Through observation and analysis of historical data in multiple dimensions, to provide decision-makers on the focus (topic) of decision support information. Thus the design is also different from the relationship model of the database, instead of using multi-dimensional data analysis model.
A data warehouse is a data analysis system platform, which uses data obtained from transactional systems, and do a summary, processing, and provide a basis for decision-makers.
Analysis system afterwards, it is to provide all of the valid period of the data concerned. These data are massive, summary calculations it should be slower, however, as long as they provide effective analytical data to achieve their goals.
Data warehouse fact and dimension tables.
Fact table generally is stored in the theme and related metrics (number) and the data table dimension and a key field for the established connections, stored in dimension table is a multi dimensional description information and key fields.
For a better understanding, we can look at this example:
For a dimension indicators of commodity marketing business analysis, requirements are listed below the target of our analysis, analysis, dimension hierarchies, etc., you can better understand what is fact table, what is the dimension table.
Our fact table is stored in record sales of goods. Dimension table is stored customer information, product information and so on.