Identifikatorius

Identifikatorius is a value that uniquely identifies an entity within a system. It functions as a stable reference used to retrieve, relate, or authorize access to that entity, thereby enabling efficient data management and communication across components.

Identifikatoriai can be natural keys or surrogate keys. Natural keys derive from intrinsic properties of the entity, such as a national ID number; surrogate keys are generated solely to provide a unique identifier, such as a UUID or an auto-incremented numeric value. In computing, identifiers appear in databases as primary keys, in software as identifiers of objects or sessions, and in networks as URIs or URLs.

Key properties of a good identifikatorius include uniqueness, stability (ideally persistent over time), and, where possible, immutability. Privacy and security considerations may lead to avoiding the exposure of personally identifying information in identifiers, and to using opaque tokens or surrogate keys. Practical identifiers should also have a clearly defined format, length limits, and support efficient indexing.

Common creation methods include UUIDs (Universally Unique Identifiers, RFC 4122), especially version 4, ULIDs, Snowflake-style IDs, and database-generated auto-increment numbers. The choice depends on requirements such as locality, sorting, or distributed generation without coordination. For human-facing systems, identifiers may be presented alongside a display name or mapped through a lookup to protect sensitive data.

In database design, identifiers often serve as primary keys and are joined to related records through foreign keys. In distributed systems, globally unique identifiers prevent collisions across components. Maintenance tasks include handling key migrations, preventing duplication, and documenting the identifiers' lifecycle. See also: identifier, UUID, primary key.