presto-main/src/main/java/io/prestosql/connector/system/jdbc/ColumnJdbcTable.java/ColumnJdbcTable/charOctetLength
class ColumnJdbcTable:    private static Integer charOctetLength(Type type)
    {
        if (isVarcharType(type)) {
            return ((VarcharType) type).getLength().orElse(VarcharType.UNBOUNDED_LENGTH);
        }
        if (isCharType(type)) {
            return ((CharType) type).getLength();
        }
        if (type.equals(VARBINARY)) {
            return Integer.MAX_VALUE;
        }
        return null;
    }