apache/iceberg · error · java.lang.IllegalArgumentException

Invalid precision: %s

Error message

Invalid precision: %s

What it means

FlinkOrcReaders.decimals() throws IllegalArgumentException 'Invalid precision: <p>' when a DECIMAL column's precision is greater than 38, because the reader only supports precision <= 18 (long-backed) and <= 38 (BigDecimal-backed). Iceberg itself caps decimal precision at 38, so this usually indicates corrupt/foreign metadata.

Source

Thrown at flink/v2.1/flink/src/main/java/org/apache/iceberg/flink/data/FlinkOrcReaders.java:69

class FlinkOrcReaders {
  private FlinkOrcReaders() {}

  static OrcValueReader<StringData> strings() {
    return StringReader.INSTANCE;
  }

  static OrcValueReader<Integer> dates() {
    return DateReader.INSTANCE;
  }

  static OrcValueReader<DecimalData> decimals(int precision, int scale) {
    if (precision <= 18) {
      return new Decimal18Reader(precision, scale);
    } else if (precision <= 38) {
      return new Decimal38Reader(precision, scale);
    } else {
      throw new IllegalArgumentException("Invalid precision: " + precision);
    }
  }

  static OrcValueReader<Integer> times() {
    return TimeReader.INSTANCE;
  }

  static OrcValueReader<TimestampData> timestamps() {
    return TimestampReader.INSTANCE;
  }

  static OrcValueReader<TimestampData> timestampTzs() {
    return TimestampTzReader.INSTANCE;
  }

  static <T> OrcValueReader<ArrayData> array(OrcValueReader<T> elementReader) {
    return new ArrayReader<>(elementReader);
  }

View on GitHub (pinned to 86d9c8fc54)

Solutions

1. Fix the schema so decimal precision is <= 38 (Iceberg max).
2. Rewrite the ORC files with a supported precision (e.g. decimal(38, s)).
3. Validate the table schema with TypeUtil/validation before scanning.

Example fix

// before
Types.DecimalType.of(50, 5)
// after
Types.DecimalType.of(38, 5)

Types.DecimalType dt = (Types.DecimalType) fieldType;
Preconditions.checkArgument(dt.precision() <= 38,
    "ORC reader supports decimal precision <= 38, got %s", dt.precision());

boolean readableDecimal(Types.DecimalType t) {
  return t.precision() <= 38;
}

try {
  reader.read(row, ordinal);
} catch (IllegalArgumentException e) {
  if (e.getMessage().startsWith("Invalid precision")) {
    // schema is outside Iceberg limits; fail fast with clear context
    throw new IllegalStateException("Decimal precision beyond Iceberg limit: " + e.getMessage());
  }
  throw e;
}

When it happens

Trigger: Reading ORC decimal columns whose declared precision exceeds 38, e.g. decimal(50, 5).

Common situations: ORC files produced by external systems allowing larger precisions; hand-built schemas with invalid precision; metadata corruption.

Understand the failure class

Background: "value must be between 0 and 1" / "out of range" / "must not be negative" errors: fixing range-validation failures across open-source libraries — this error's family across 42 libraries.

Related errors

• Invalid precision: %s
• Invalid precision: ${precision}
• Invalid precision: ${precision}
• Invalid precision:
• Invalid precision:

AI-assisted analysis of apache/iceberg@86d9c8fc54 (2026-09-12). Data as JSON: /api/errors/dfacf157c4940523. Report an issue: GitHub.