```
$ echo '20210101,A' | clickhouse-local --input-format CSV --structure 'd Date, s String' --query "SELECT * FROM table"
Code: 27. DB::Exception: Cannot parse input: expected ',' before: '20210101,A\n': 
Row 1:
Column 0,   name: d, type: Date,   ERROR: text "20210101,A" is not like Date

: While executing ParallelParsingBlockInputFormat: While executing File. (CANNOT_PARSE_INPUT_ASSERTION_FAILED)
```

**How to solve**

Disambiguate while parsing by absense of separators between YYYY-MM-DD.
{
    readPODBinary(x, buf);
}
template <typename T>
inline void readFloatBinary(T & x, ReadBuffer & buf)
{
    readPODBinary(x, buf);
}
inline void readStringBinary(std::string & s, ReadBuffer & buf, size_t MAX_STRING_SIZE = DEFAULT_MAX_STRING_SIZE)
{
    size_t size = 0;
    readVarUInt(size, buf);
    if (size > MAX_STRING_SIZE)
        throw Poco::Exception("Too large string size.");
    s.resize(size);
    buf.readStrict(s.data(), size);
}
inline StringRef readStringBinaryInto(Arena & arena, ReadBuffer & buf)
{
    size_t size = 0;
    readVarUInt(size, buf);
    char * data = arena.alloc(size);
    buf.readStrict(data, size);
    return StringRef(data, size);
}
template <typename T>
void readVectorBinary(std::vector<T> & v, ReadBuffer & buf, size_t MAX_VECTOR_SIZE = DEFAULT_MAX_STRING_SIZE)