apache/iceberg · error · IllegalArgumentException

Invalid precision: ${precision}

Error message

Invalid precision: ${precision}

What it means

FlinkOrcWriters.decimals selects a decimal writer by precision: <=18 long-backed, <=38 byte-backed. Precision > 38 is invalid under Iceberg's decimal spec and throws IllegalArgumentException 'Invalid precision'.

Source

Thrown at flink/v1.20/flink/src/main/java/org/apache/iceberg/flink/data/FlinkOrcWriters.java:87

  static OrcValueWriter<TimestampData> timestampTzs() {
    return TimestampTzWriter.INSTANCE;
  }

  static OrcValueWriter<TimestampData> timestampNanos() {
    return TimestampNanoWriter.INSTANCE;
  }

  static OrcValueWriter<TimestampData> timestampNanoTzs() {
    return TimestampNanoTzWriter.INSTANCE;
  }

  static OrcValueWriter<DecimalData> decimals(int precision, int scale) {
    if (precision <= 18) {
      return new Decimal18Writer(precision, scale);
    } else if (precision <= 38) {
      return new Decimal38Writer(precision, scale);
    } else {
      throw new IllegalArgumentException("Invalid precision: " + precision);
    }
  }

  static <T> OrcValueWriter<ArrayData> list(
      OrcValueWriter<T> elementWriter, LogicalType elementType) {
    return new ListWriter<>(elementWriter, elementType);
  }

  static <K, V> OrcValueWriter<MapData> map(
      OrcValueWriter<K> keyWriter,
      OrcValueWriter<V> valueWriter,
      LogicalType keyType,
      LogicalType valueType) {
    return new MapWriter<>(keyWriter, valueWriter, keyType, valueType);
  }

  static OrcValueWriter<RowData> struct(List<OrcValueWriter<?>> writers, List<LogicalType> types) {
    int[] fieldIndexes = new int[writers.size()];

View on GitHub (pinned to 86d9c8fc54)

Solutions

1. Correct the schema so decimal precision is <= 38
2. Validate decimal types (TypeUtil) before committing the schema or starting the write
3. Rewrite table metadata if it contains an invalid decimal definition

Example fix

// before
DecimalType(50, 10) -> decimals() throws
// after
DecimalType(38, 10)

if (precision < 1 || precision > 38) throw new IllegalArgumentException("decimal precision must be 1..38");

boolean validDecimal(int p) { return p >= 1 && p <= 38; }

try { writer = FlinkOrcWriters.decimals(p, s); } catch (IllegalArgumentException e) { /* fix schema */ throw e; }

When it happens

Trigger: FlinkOrcWriters.decimals(precision, scale) invoked with precision > 38, typically from FlinkOrcWriter for an out-of-spec decimal column.

Common situations: Out-of-spec schemas from external tools or manual schema construction; corrupted metadata claiming a huge precision.

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

AI-assisted analysis of apache/iceberg@86d9c8fc54 (2026-09-12). Data as JSON: /api/errors/018c2680e2ce5ea8. Report an issue: GitHub.