Designing queries and establishing a data dictionary are important. Decisions should be informed by the Data Protection Act. Entities, attributes and relationships should be clearly defined.
Data dictionaries are created during the design phase to define the structure of a database.
Creating relational database management systems can be time consuming, and a data dictionary will act as an efficient reference point during implementation.
Data dictionaries contain the following metadata.
name of each entity
name of all attributes associated with each entity
type of data that will be held by each attribute
size of each attribute (taking account of the overall file size to be held in RAM or backing storage)
indication of attributes that will be used as primary or foreign keys during implementation
validation rules that are to be applied to attributes