pentaho/pentaho-kettle · error · KettleValueException

: I don't know how to convert binary values to BigDecimals.

Error message

 : I don't know how to convert binary values to BigDecimals.

What it means

ValueMetaBase.getBigNumber() converts a stored value to BigDecimal but has no conversion path for TYPE_BINARY (byte[]) values. The library refuses to guess a binary-to-numeric interpretation, so it throws KettleValueException with this message, prefixed by the field's toString(). It signals an incorrectly typed field in the row metadata rather than a data-value problem.

Solutions

  1. Fix the field's metadata type to TYPE_NUMBER/TYPE_BIGNUMBER (or Integer) so a numeric conversion exists
  2. Decode the bytes yourself (e.g. new String(bytes) then new BigDecimal(s)) before requesting a BigNumber
  3. Reject/repair the upstream step that produces binary data where a number is expected

Example fix

// before
ValueMetaInterface meta = new ValueMetaBase("amount", ValueMetaInterface.TYPE_BINARY);
BigDecimal v = meta.getBigNumber(data); // throws
// after
ValueMetaInterface meta = new ValueMetaBase("amount", ValueMetaInterface.TYPE_BIGNUMBER);
meta.setConversionMask("#,##0.00");
BigDecimal v = meta.getBigNumber(meta.convertDataCompatibility(...)); // proper numeric metadata
Defensive patterns

Strategy: validation

Validate before calling

if (meta == null || meta.getType() == ValueMetaInterface.TYPE_BINARY) {
  throw new IllegalArgumentException("Field '" + (meta != null ? meta.getName() : "?") + "' is BINARY; cannot read as BigNumber");
}
BigDecimal v = meta.getBigNumber(value);

Type guard

boolean isNumericReadable(ValueMetaInterface m) {
  int t = m.getType();
  return t == ValueMetaInterface.TYPE_BIGNUMBER || t == ValueMetaInterface.TYPE_NUMBER
      || t == ValueMetaInterface.TYPE_INTEGER || t == ValueMetaInterface.TYPE_STRING;
}

Try / catch

try {
  BigDecimal v = meta.getBigNumber(value);
} catch (KettleValueException e) {
  log.warn("Cannot convert field " + meta.getName() + " to BigDecimal: " + e.getMessage());
  // fallback: decode bytes or skip row
}

Prevention

When it happens

Trigger: Calling getBigNumber(object) (directly or via row.getNumber()/RowMeta.getBigNumber) on a ValueMeta whose type is TYPE_BINARY, regardless of storage type.

Common situations: A step or UDF sets a field as binary (e.g. raw bytes from a file or network payload) while downstream code treats it as numeric; metadata built with ValueMetaFactory or new ValueMetaBase(name, ValueMetaInterface.TYPE_BINARY) then read as a number; CSV/binary input steps that classify a column as Binary instead of Number.

Understand the failure class

Background: "is not a compatible type" / "cannot merge" errors: when a value's type doesn't match what the library requires — this error's family across 65 libraries.

Related errors

AI-assisted analysis of pentaho/pentaho-kettle@f3058517a1 (2026-09-13). Data as JSON: /api/errors/c551537b078beed0. Report an issue: GitHub.

Appendix: source

Thrown at core/src/main/java/org/pentaho/di/core/row/value/ValueMetaBase.java:2215

              return convertDateToBigNumber( (Date) convertBinaryStringToNativeType( (byte[]) object ) );
            case STORAGE_TYPE_INDEXED:
              return convertDateToBigNumber( (Date) index[( (Integer) object ).intValue()] );
            default:
              throw new KettleValueException( toString() + " : Unknown storage type " + storageType + " specified." );
          }
        case TYPE_BOOLEAN:
          switch ( storageType ) {
            case STORAGE_TYPE_NORMAL:
              return convertBooleanToBigNumber( (Boolean) object );
            case STORAGE_TYPE_BINARY_STRING:
              return convertBooleanToBigNumber( (Boolean) convertBinaryStringToNativeType( (byte[]) object ) );
            case STORAGE_TYPE_INDEXED:
              return convertBooleanToBigNumber( (Boolean) index[( (Integer) object ).intValue()] );
            default:
              throw new KettleValueException( toString() + " : Unknown storage type " + storageType + " specified." );
          }
        case TYPE_BINARY:
          throw new KettleValueException( toString() + " : I don't know how to convert binary values to BigDecimals." );
        case TYPE_SERIALIZABLE:
          throw new KettleValueException( toString() + " : I don't know how to convert serializable values to BigDecimals." );
        default:
          throw new KettleValueException( toString() + " : Unknown type " + type + " specified." );
      }
    } catch ( Exception e ) {
      throw new KettleValueException( "Unexpected conversion error while converting value [" + toString()
          + "] to a BigNumber", e );
    }
  }

  @Override
  public Boolean getBoolean( Object object ) throws KettleValueException {
    if ( object == null ) {
      return null;
    }
    switch ( type ) {
      case TYPE_BOOLEAN:

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