SQLSTATE 38004 ERROR Class 38: External Routine Exception

reading_sql_data_not_permitted Reading Sql Data Not Permitted — SQLSTATE 38004

SQLSTATE 38004 (reading_sql_data_not_permitted): An external (C) routine raised an error.

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Last reviewed May 2025 Grounded in source

Symptoms

The server reports SQLSTATE 38004 (reading_sql_data_not_permitted), a condition in the External Routine Exception class.

  • The error is written to the server log and returned to the client carrying SQLSTATE 38004.
  • 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 reading_sql_data_not_permitted 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

38004 belongs to Class 38 — External Routine Exception. In this class, an external (C) routine raised an error.

The first two characters (38) identify the error class, so application code can match the whole class via 38000 when the specific code is not needed.

Diagnostic Queries

Recovery

Check the external function or extension implementation and its inputs.

Reference: PostgreSQL error codes — Class 38 (External Routine Exception).

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