uniqueId

A uniqueId is an identifier assigned to an object, record, or entity to distinguish it from others within a given scope or system. The goal is to provide a value that is highly unlikely to collide with other identifiers, enabling reliable reference, retrieval, and linking across components such as databases, services, and user interfaces.

Common forms include UUIDs or GUIDs, widely used across platforms and defined by standards such as RFC 4122. A typical UUID is a 128‑bit value presented as a 36-character string with hyphens, for example 123e4567-e89b-12d3-a456-426614174000. Other formats include ULIDs, which are time-ordered 128-bit identifiers encoded in Crockford's base32, and database-specific IDs like MongoDB’s ObjectId or Twitter’s Snowflake IDs, which combine time information with randomness or machine identifiers.

Generation methods vary and may be random, time-based, or a combination. Library or database features usually provide uniqueId generation, ensuring that newly created objects receive distinct identifiers without centralized coordination. Usage scenarios include primary keys and foreign keys in databases, tokens for API authentication, filenames, session identifiers, and cross-system references.

Considerations when using uniqueIds include the probability of collision, length and readability, privacy and security implications, and indexing performance. In distributed or multi-system environments, adopting a namespace or composite approach can reduce collision risk. It is also important to balance determinism and unpredictability according to the use case, as some applications require reproducible IDs while others benefit from randomness.