andmekiht

Andmekiht is a term used in Estonian information technology to denote the data layer of a software system. It encompasses the components and services that manage data storage, retrieval, and persistence, acting as an abstraction over the underlying data sources such as relational databases, document stores, and external APIs. In a multilayer architecture, andmekiht sits between the business logic layer and the data sources, exposing a set of stable interfaces to the rest of the application while shielding higher layers from data source specifics.

Key responsibilities include mapping between in-memory data structures and data storage formats, handling queries and updates, enforcing data integrity, and coordinating transactions. Common implementations use patterns such as repositories or data access objects (DAOs) and employ object-relational mapping (ORM) tools, query builders, or direct data access code. Caching, data transformation, indexing, and data migration are also typically managed within the andmekiht.

Design considerations include separation of concerns, testability, performance, and security. The layer often defines data contracts or schemas and may provide data validation at the boundary to enforce consistency. In distributed systems and microservices, each service may implement its own andmekiht, sometimes sharing common data models but isolating persistence logic from business rules and presentation concerns.

Relation to other layers: the presentation layer interacts with the andmekiht through services or repositories, while the domain model or business logic remains independent of how data is stored. Evolution of the andmekiht mirrors broader trends in data management, such as microservice architectures, polyglot persistence, and schema evolution.