1. definition
1.1. a collection of logically related data, used to model a reality
2. Design
2.1. IN FOUR PHASES
2.1.1. Collection and analysis of requirements
2.1.1.1. Through contacts of any kind, users provide to designer data, processes, constraints
2.1.2. Conceptual design
2.1.2.1. Through contacts of any kind, users provide to designer data, processes, constraints
2.1.3. Logical design
2.1.3.1. The conceptual model is transformed into a logical scheme
2.1.3.1.1. relational
2.1.3.1.2. reticular
2.1.3.1.3. hierarchic
2.1.4. Physical design
2.1.4.1. storage structures and their parameters are defined
2.2. DESCRIPTION OF DATA
2.2.1. logical models
2.2.2. semantic models
3. how is it managed
3.1. The DBMS is responsible for the storage, organization and Data Management
3.1.1. REDUNDANCIES
3.1.1.1. redundancy means both the duplication of the data, both the storing a data that results from the processing of other
3.1.2. INCONSISTENCIES
3.1.2.1. inconsistency means when two data representing the same information have different values
3.1.3. INTEGRITY OF DATA
3.1.3.1. Check that the inclusion of new data, or cancellation of the existing ones do not alter the consistency of the base of data
3.1.4. In the organization of the databases we highlight three levels of abstraction
3.1.4.1. EXTERNAL
3.1.4.2. LOGICAL
3.1.4.3. INTERNAL