```
$ 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.
{
    if (!buf.eof()
        && buf.position() + 3 < buf.buffer().end()
        && buf.position()[0] == '\xEF'
        && buf.position()[1] == '\xBB'
        && buf.position()[2] == '\xBF')
    {
        buf.position() += 3;
    }
}
void skipToNextLineOrEOF(ReadBuffer & buf);
void skipToCarriageReturnOrEOF(ReadBuffer & buf);
void skipToUnescapedNextLineOrEOF(ReadBuffer & buf);
/** This function just copies the data from buffer's internal position (in.position())
  * to current position (from arguments) into memory.
  */
void saveUpToPosition(ReadBuffer & in, Memory<Allocator<false>> & memory, char * current);
/** This function is negative to eof().
  * In fact it returns whether the data was loaded to internal ReadBuffers's buffer or not.
  * And saves data from buffer's position to current if there is no pending data in buffer.
  * Why we have to use this strange function? Consider we have buffer's internal position in the middle
  * of our buffer and the current cursor in the end of the buffer. When we call eof() it calls next().
  * And this function can fill the buffer with new data, so we will lose the data from previous buffer state.
  */
bool loadAtPosition(ReadBuffer & in, Memory<Allocator<false>> & memory, char * & current);
struct PcgDeserializer
{
    static void deserializePcg32(pcg32_fast & rng, ReadBuffer & buf)