SQLSTATE 0F001 ERROR Class 0F: Locator Exception

invalid_locator_specification Invalid Locator Specification — SQLSTATE 0F001

SQLSTATE 0F001 (invalid_locator_specification): A large-object locator is invalid.

PG 12, 13, 14, 15, 16, 17, 18 Official docs
Last reviewed May 2025 Grounded in source

Symptoms

The server reports SQLSTATE 0F001 (invalid_locator_specification), a condition in the Locator Exception class.

  • The error is written to the server log and returned to the client carrying SQLSTATE 0F001.
  • Any driver (libpq, JDBC, psycopg, npgsql, pgx) surfaces this code in its error object so you can branch on it programmatically.
  • PL/pgSQL can trap it by name: EXCEPTION WHEN invalid_locator_specification THEN.

Environment

Severity: ERROR  |  PostgreSQL versions: 12, 13, 14, 15, 16, 17

Reproduce with the exact statement and read the full message in the server log (raise log_min_messages / set log_min_error_statement for more context).

Root Cause

0F001 belongs to Class 0F — Locator Exception. In this class, a large-object locator is invalid.

The first two characters (0F) identify the error class, so application code can match the whole class via 0F000 when the specific code is not needed.

Diagnostic Queries

Recovery

Ensure the large-object handle is open and valid for the current transaction before using it.

Reference: PostgreSQL error codes — Class 0F (Locator Exception).

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