presto-orc/src/main/java/io/prestosql/orc/metadata/OrcMetadataReader.java/OrcMetadataReader/toDecimalStatistics
class OrcMetadataReader:    private static DecimalStatistics toDecimalStatistics(OrcProto.DecimalStatistics decimalStatistics)
    {
        BigDecimal minimum = decimalStatistics.hasMinimum() ? new BigDecimal(decimalStatistics.getMinimum()) : null;
        BigDecimal maximum = decimalStatistics.hasMaximum() ? new BigDecimal(decimalStatistics.getMaximum()) : null;

        // could be long (16 bytes) or short (8 bytes); use short for estimation
        return new DecimalStatistics(minimum, maximum, SHORT_DECIMAL_VALUE_BYTES);
    }