system() — PostgreSQL built-in function

system(): SYSTEM tablesample method handler. PostgreSQL miscellaneous functions — signature, volatility, version applicability and an illustrative example.

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

Summary

system is a PostgreSQL built-in function in the Miscellaneous Functions group. PostgreSQL’s system catalog (pg_proc) describes it as: “SYSTEM tablesample method handler”.

Signature

system(internal) → tsm_handler

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: tsm_handler

Example

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

SELECT system(NULL::internal);

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

system 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.