Why build a data warehouse?

Why build a data warehouse? Because the traditional transactional database can not meet the needs of information analysis.

Expand:

Characteristics of data warehouse:

1, data warehouse is used to support decision-making and help people analyze and process data, which is different from operational database.

2. Data warehouse is an effective integration of multiple heterogeneous data sources, which can be reorganized according to the theme. For the convenience of analysis, it contains historical data, and the data stored in the data warehouse will generally not be modified.