ts_rank() — PostgreSQL full-text-search function

ts_rank(): relevance. PostgreSQL full text search functions — signature, volatility, version applicability and an illustrative example.

The Sev-1 Admin
The Sev-1 Admin  ·  2 min read

Summary

ts_rank is a PostgreSQL built-in function in the Full Text Search Functions group. PostgreSQL’s system catalog (pg_proc) describes it as: “relevance”.

Signature

ts_rank has 4 documented overloaded forms:

ts_rank(real[], tsvector, tsquery, integer) → real
ts_rank(real[], tsvector, tsquery) → real
ts_rank(tsvector, tsquery, integer) → real
ts_rank(tsvector, tsquery) → real

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: Full Text Search Functions
  • Kind: Function
  • Volatility: IMMUTABLE — Marked IMMUTABLE — it always returns the same result for the same arguments and can be used in indexes and other contexts that require immutability.
  • Returns: real

Example

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

SELECT ts_rank(ARRAY[3.14, 3.14], to_tsvector('a fat cat'), to_tsquery('cat'), 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

ts_rank 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 — Full Text Search Functions.