What is the primary purpose of a data dictionary?

The primary purpose of a data dictionary is to document data attributes and definitions. A data dictionary serves as a centralized repository that contains detailed information about the data being used in a database. This includes specifics such as data types, lengths, acceptable values, and relationships between different data fields. Having this information readily available helps users understand the data, ensures consistency across the database, and aids in data management practices.

By explicitly defining the characteristics and semantics of the data, a data dictionary enhances communication among stakeholders, such as database administrators, developers, and end-users. It acts as a reference tool for anyone working with the data, making it easier to create, access, and manage databases effectively. This documentation is crucial for database design, integrity, and maintenance.

In contrast, other options focus on different aspects of data management. Assigning unique identifiers to data entries pertains more to database normalization and integrity constraints rather than the documentation of data itself. Establishing relational database structures is concerned with defining how tables and relationships are organized rather than providing descriptions of the data. Optimizing database performance relates to improving the efficiency of data access and manipulation, which is a separate focus from the purpose of a data dictionary.