apache/druid · error · IllegalArgumentException

No such system field

Error message

No such system field[%s]

What it means

SystemField.fromFieldName looks up a system field (such as __partition_column or __file) by its column name and throws this IllegalArgumentException when no registered enum constant matches the given field name.

Solutions

1. Use an exact supported system field name (e.g. __file, __partition_column)
2. Check spelling and double-underscore prefix
3. Consult SystemField enum for the list of valid names in your Druid version

Example fix

// before
SELECT __parition_column FROM TABLE(EXTERN(...))
// after
SELECT __partition_column FROM TABLE(EXTERN(...))

boolean known = Arrays.stream(SystemField.values()).anyMatch(f -> f.getFieldName().equals(name));

Optional<SystemField> safeFromFieldName(String n) { try { return Optional.of(SystemField.fromFieldName(n)); } catch (IllegalArgumentException e) { return Optional.empty(); } }

try { SystemField.fromFieldName(name); } catch (IllegalArgumentException e) { log.error("Unknown system field {}", name); }

When it happens

Trigger: Referencing a system field column name in an MSQ/ingestion query or spec that does not equal any SystemField's getFieldName(), e.g. a typo like '__parition_column' or an unsupported field name.

Common situations: Typoed system field names in SQL queries against external input, copying field names from older Druid versions where names changed, case mismatches.

Understand the failure class

Background: Invalid enum value errors: "Unknown type", "Invalid scope", "must be one of" — when a string is not on the library's allowed list — this error's family across 23 libraries.

Related errors

• argument must be a LONG constant
• Cannot filter datasource
• Cannot handle constant condition
• Cannot handle equality condition involving left-hand…
• Cannot handle non-equijoin condition

AI-assisted analysis of apache/druid@9b90983fd2 (2026-09-07). Data as JSON: /api/errors/b3865d8745084012. Report an issue: GitHub.

Appendix: source

Thrown at processing/src/main/java/org/apache/druid/data/input/impl/systemfield/SystemField.java:60

  private final String fieldName;
  private final ColumnType columnType;

  SystemField(final String fieldName, final ColumnType columnType)
  {
    this.fieldName = fieldName;
    this.columnType = columnType;
  }

  @JsonCreator
  public static SystemField fromFieldName(final String fieldName)
  {
    for (final SystemField field : values()) {
      if (field.getFieldName().equals(fieldName)) {
        return field;
      }
    }

    throw new IAE("No such system field[%s]", fieldName);
  }

  /**
   * Name of this system field.
   */
  @JsonValue
  public String getFieldName()
  {
    return fieldName;
  }

  /**
   * Type of this system field.
   */
  @SuppressWarnings("unused") // Not used, but still useful for signifying intent
  public ColumnType getColumnType()
  {
    return columnType;

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