Databasstruktur

Databasstruktur, or database structure, refers to the organization of data elements and the relationships between them within a database. It encompasses how data is modeled, stored, and accessed, and includes both logical design (how data relates to one another) and physical design (how data is stored on hardware).

In relational databases, the core elements are tables, columns, data types, and constraints. Tables group related records; columns define attributes; rows hold data. Keys establish relationships: primary keys uniquely identify records, and foreign keys enforce referential integrity between tables. Normalization organizes data to reduce redundancy through normal forms; denormalization may be used to optimize certain read patterns. Indexes speed up queries, and partitions or sharding distribute data across storage.

In NoSQL databases, the structure is more flexible. Document stores use collections of documents with varying fields; key-value stores map keys to values; column-family stores organize data into column families; graph databases model nodes and edges. Data schemas may be implicit or defined at the application level, and schema evolution is common as requirements change.

Design considerations include data integrity, consistency models, scalability, and maintainability. A data dictionary and metadata catalog help document the schema and constraints. Normalization versus denormalization, indexing strategies, and physical layout influence performance and storage efficiency.

A well-structured databasstruktur supports reliable data access, easier maintenance, and predictable performance. It provides a foundation for data governance, migration, and integration across systems.