unique_key_recheck() — PostgreSQL built-in function

unique_key_recheck(): deferred UNIQUE constraint check. PostgreSQL miscellaneous functions — signature, volatility, version applicability and an illustrative example.

The Sev-1 Admin
The Sev-1 Admin  ·  1 min read

Summary

unique_key_recheck is a PostgreSQL built-in function in the Miscellaneous Functions group. PostgreSQL’s system catalog (pg_proc) describes it as: “deferred UNIQUE constraint check”.

Signature

unique_key_recheck() → trigger

Argument and return types are taken from the pg_proc catalog; internal type names are shown using their readable SQL spellings (for example int4 is shown as integer). (Derived from the catalog — see the linked reference for the canonical documentation.)

Classification

  • Category: Miscellaneous Functions
  • Kind: Function
  • Volatility: VOLATILE — Marked VOLATILE — its result can change even within a single statement (for example, it may depend on time, sequences or the current session).
  • Returns: trigger

Example

Illustrative form (replace placeholder values with your own data):

SELECT unique_key_recheck();

The example above is illustrative and is meant to show calling syntax only; consult the linked PostgreSQL documentation for exact semantics, edge cases and accepted argument combinations.

Version applicability

unique_key_recheck is present across the surveyed releases (PostgreSQL 15, 16, 17, 18, 19). On older major versions, behaviour may differ in detail — always check the documentation for the version you run.

Related & references

Reference: PostgreSQL documentation — Miscellaneous Functions.