insufficient_privilege permission denied for function … — 42501

Symptoms

A role lacked the EXECUTE privilege required to call a function or procedure. PostgreSQL raises SQLSTATE 42501 (insufficient_privilege).

• Missing EXECUTE on the function/procedure.
• Common after revoking PUBLIC execute or for new roles.
• Function privileges are separate from schema/table privileges.

What the server log shows

ERROR:  permission denied for function calculate_totals

Why PostgreSQL raises this — what the manual says

As the GRANT reference (Description) explains:

Calling a function or procedure requires the EXECUTE privilege; the role invoking it was not granted EXECUTE on that routine (and is not its owner or a superuser), so PostgreSQL refuses the call.

Calling a function requires the EXECUTE privilege on it. Without that grant (or membership in a role that has it), PostgreSQL denies the call with 42501.

Common causes

• The role lacks EXECUTE on the function.
• EXECUTE was revoked from PUBLIC and not granted to the role.
• A new role not covered by default privileges.

How to fix it

1. Grant it: GRANT EXECUTE ON FUNCTION calculate_totals() TO app_user;.
2. Set default privileges for functions created later.
3. Also ensure the role has USAGE on the function’s schema.

Related & next steps

• SQLSTATE 42501 — Insufficient Privilege (full reference)
• Message: permission denied for sequence
• Glossary: Function

Reference: PostgreSQL 18 — GRANT.