Databaseniveauets

Databaseniveauets is a concept in software engineering describing the layer of a multi-tier information system responsible for data storage, persistence, and access. In a typical three-tier architecture it sits between the application logic (business layer) and external data sources or back-end systems. The term is used mainly in Danish-language IT literature to distinguish the database layer from the presentation and application layers.

The databaseniveauet usually comprises a database management system (DBMS), data schemas, tables, indexes, stored procedures, and data access interfaces. It can also include data warehouses or data lakes in larger architectures. The database layer provides data models and operating rules that govern how data is stored and retrieved.

Responsibilities include data integrity through constraints and transactions (ACID properties where applicable), performance optimization (indexes, query plans), security (authentication, authorization, encryption), backup and recovery, and disaster recovery planning. It also handles data migration and versioning when schema evolves.

Interaction with other layers typically occurs through data access layers, ORMs, or SQL- and API-based queries. The databaseniveauets is often managed by a database administrator or a team, and may be deployed as centralized databases or distributed systems with replication and sharding. It may also support caching and materialized views to improve performance.

Terminology varies by language and framework; in some contexts databaseniveauet or data access layer are used to describe similar concerns. When distinguishing layers, designers consider coupling, data independence, and the balance of responsibilities between the databaseniveauets and higher layers.