**Describe the situation**
https://markify.dev/p/zfrQMV2/text

**How to reproduce**
On aws `c5ad.24xlarge` run a query:

```
SET max_memory_usage = '100G', max_threads = 1000, max_insert_threads = 96

INSERT INTO wikistat WITH
    parseDateTimeBestEffort(extract(toLowCardinality(_path), 'pageviews-([\\d\\-]+)\\.gz$')) AS time,
    splitByChar(' ', line) AS values,
    splitByChar('.', values[1]) AS projects
SELECT
    time,
    projects[1] AS project,
    projects[2] AS subproject,
    values[2] AS path,
    CAST(values[3], 'UInt64') AS hits
FROM s3('https://....s3.eu-central-1.amazonaws.com/wikistat/original/*.gz', '...', '...', LineAsString, auto)
WHERE length(values) >= 3
```

Performance is not bad (22 million rows are inserted per second) but can be better.
{
    ++buf.position();
    if (buf.eof())
        throw Exception("Cannot parse escape sequence", ErrorCodes::CANNOT_PARSE_ESCAPE_SEQUENCE);
    char char_after_backslash = *buf.position();
    if (char_after_backslash == 'x')
    {
        ++buf.position();
        
        char hex_code[2];
        readPODBinary(hex_code, buf);
        s.push_back(unhex2(hex_code));
    }
    else if (char_after_backslash == 'N')
    {
        
        ++buf.position();
    }
    else
    {
        
        char decoded_char = parseEscapeSequence(char_after_backslash);