pg_try_advisory_xact_lock_shared() — PostgreSQL hashing/encoding function

pg_try_advisory_xact_lock_shared(): obtain shared advisory lock if available. PostgreSQL hashing & encoding functions — signature, volatility, version applicability and an illustrative example.

Summary

pg_try_advisory_xact_lock_shared is a PostgreSQL built-in function in the Hashing & Encoding Functions group. PostgreSQL’s system catalog (pg_proc) describes it as: “obtain shared advisory lock if available”.

Signature

pg_try_advisory_xact_lock_shared has 2 documented overloaded forms:

pg_try_advisory_xact_lock_shared(bigint) → boolean
pg_try_advisory_xact_lock_shared(integer, integer) → boolean

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: Hashing & Encoding 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: boolean

Example

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

SELECT pg_try_advisory_xact_lock_shared(42);

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

pg_try_advisory_xact_lock_shared 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 — Hashing & Encoding Functions.