tengslagagnagrunnar

Tengslagagnagrunnar is the Icelandic term used to describe relational databases, a class of database management systems (DBMS) that organize data into tables with predefined schemas and support relations between tables via keys. They use a declarative SQL language for querying and updating data.

The data model centers on tables, rows, and columns. Each table has a primary key that uniquely identifies its rows, and foreign keys that establish relationships to other tables. Normalization reduces redundancy, while indexes speed up lookups and joins.

Operations are governed by ACID properties—Atomicity, Consistency, Isolation, and Durability—ensuring reliable transactions. SQL provides data definition and manipulation capabilities, with common statements like SELECT, INSERT, UPDATE, and DELETE and support for JOINs, constraints, and triggers.

Relational databases emerged from the relational model proposed by E. F. Codd in 1970 and became dominant in the 1980s and 1990s. They remain widely used in business applications, from finance to inventory management, with major systems such as Oracle, MySQL, PostgreSQL, and SQL Server.

In modern contexts, distributed relational databases and NewSQL variants extend scalability while preserving ACID semantics. Cloud-based offerings and integration with data warehouses are common, while some teams complement relational databases with NoSQL stores for specific workloads.

Tengslagagnagrunnar are well suited for structured data with clear relationships, strong data integrity, and well-defined schemas. Design decisions around normalization, indexing, and transaction requirements influence performance, scalability, and maintainability in organizational IT environments.