apache/iceberg · error · UnsupportedOperationException

Unsupported decimal precision:

Error message

Unsupported decimal precision: 

What it means

Variants.of(BigDecimal) maps a decimal to a PhysicalType based on precision: DECIMAL4 (<=9), DECIMAL8 (10-18), DECIMAL16 (<=38). The variant spec caps decimal precision at 38, so any precision above 38 throws UnsupportedOperationException because no variant physical encoding exists for it.

Solutions

1. Reduce the BigDecimal precision to <=38 via value.setScale(..., roundingMode) or value.round(mathContext)
2. Check precision before conversion and reject/alter oversized decimals
3. Use a non-variant storage path for decimals with precision > 38

Example fix

// before
VariantPrimitive<BigDecimal> v = Variants.of(bigValue);
// after
BigDecimal capped = bigValue.round(new MathContext(38));
VariantPrimitive<BigDecimal> v = Variants.of(capped);

if (value.precision() > 38) { throw new IllegalArgumentException("Decimal precision " + value.precision() + " exceeds variant max 38"); }

boolean isVariantCompatible(BigDecimal v) { return v.precision() <= 38; }

try { return Variants.of(value); } catch (UnsupportedOperationException e) { return null; /* or serialize as string */ }

When it happens

Trigger: Calling Variants.of(BigDecimal) with a BigDecimal whose precision() > 38, e.g. new BigDecimal("12345678901234567890123456789012345678901234567890") or computed division results with huge precision.

Common situations: High-precision financial computations or BigDecimal division producing expanded precision beyond 38 digits; schema columns declared decimal(39+) being converted to variants.

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:
• Invalid precision:
• Invalid precision
• Invalid precision
• Invalid precision

AI-assisted analysis of apache/iceberg@86d9c8fc54 (2026-09-12). Data as JSON: /api/errors/2e3b705f83b977fa. Report an issue: GitHub.

Appendix: source

Thrown at core/src/main/java/org/apache/iceberg/variants/Variants.java:202

    return new PrimitiveWrapper<>(PhysicalType.TIMESTAMPNTZ, value);
  }

  public static VariantPrimitive<Long> ofIsoTimestampntz(String value) {
    return ofTimestampntz(DateTimeUtil.isoTimestampToMicros(value));
  }

  public static VariantPrimitive<BigDecimal> of(BigDecimal value) {
    int precision = value.precision();

    if (precision >= 1 && precision <= 9) {
      return new PrimitiveWrapper<>(PhysicalType.DECIMAL4, value);
    } else if (precision >= 10 && precision <= 18) {
      return new PrimitiveWrapper<>(PhysicalType.DECIMAL8, value);
    } else if (precision <= 38) {
      return new PrimitiveWrapper<>(PhysicalType.DECIMAL16, value);
    }

    throw new UnsupportedOperationException("Unsupported decimal precision: " + precision);
  }

  public static VariantPrimitive<ByteBuffer> of(ByteBuffer value) {
    return new PrimitiveWrapper<>(PhysicalType.BINARY, value);
  }

  public static VariantPrimitive<String> of(String value) {
    return new PrimitiveWrapper<>(PhysicalType.STRING, value);
  }

  public static VariantPrimitive<Long> ofTime(long value) {
    return new PrimitiveWrapper<>(PhysicalType.TIME, value);
  }

  public static VariantPrimitive<Long> ofIsoTime(String value) {
    return ofTime(DateTimeUtil.isoTimeToMicros(value));
  }

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