mxid_age() — PostgreSQL built-in function

mxid_age(): age of a multi-transaction ID, in multi-transactions before current multi-transaction. PostgreSQL miscellaneous functions — signature, volatility, version applicability and an illustrat…

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

Summary

mxid_age is a PostgreSQL built-in function in the Miscellaneous Functions group. PostgreSQL’s system catalog (pg_proc) describes it as: “age of a multi-transaction ID, in multi-transactions before current multi-transaction”.

Signature

mxid_age(xid) → integer

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: STABLE — Marked STABLE — within a single statement it returns a consistent result for the same arguments, but the result can change between statements.
  • Returns: integer

Example

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

SELECT mxid_age(NULL::xid);

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

mxid_age 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.