Idszámítás

Idszámítás is a term used in information technology to describe the process of generating and validating identification numbers or identifiers within systems. It encompasses methods for creating unique values that can identify records, users, documents, or other entities, as well as mechanisms to detect invalid inputs.

Common approaches to idszámítás include sequential (auto-increment) identifiers, which are simple and fast within a single database but can raise concerns about predictability and horizontal scaling. Universally unique identifiers (UUIDs or GUIDs) provide cross-system uniqueness without central coordination, typically in 128-bit formats with various versions (random, time-based). Time-based and ordered IDs, such as Snowflake-style schemes, combine timestamps with worker identifiers and sequences to preserve ordering and scalability across distributed systems. Hash-based IDs derive identifiers from content or attributes using cryptographic or non-cryptographic hash functions, trading deterministic mapping for potential collisions that must be managed. Check digit systems, using algorithms like Luhn or Verhoeff, validate IDs and help catch input errors in contexts such as credit cards, barcodes, and national identifiers. Composite or natural keys merge several fields to form an identifier, offering readability but potentially complicating updates and storage.

Key design considerations include ensuring uniqueness and collision resistance, controlling length and readability, supporting privacy and security, and balancing performance with storage and querying needs. Idszámítás is widely applied in databases as primary or surrogate keys, in document and product numbering, user account identifiers, and regulatory or compliance contexts. Related concepts include UID, GUID/UUID, surrogate keys, and check-digit schemes.