**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.
{
    return parse<T>(str.data(), str.size());
}
template <typename ReturnType = void>
ReturnType readDateTimeTextFallback(time_t & datetime, ReadBuffer & buf, const DateLUTImpl & date_lut);
/** In YYYY-MM-DD hh:mm:ss or YYYY-MM-DD format, according to specified time zone.
  * As an exception, also supported parsing of unix timestamp in form of decimal number.
  */
template <typename ReturnType = void>
inline ReturnType readDateTimeTextImpl(time_t & datetime, ReadBuffer & buf, const DateLUTImpl & date_lut)
{
    
    const char * s = buf.position();
    
    static constexpr auto DateTimeStringInputSize = 19;
    bool optimistic_path_for_date_time_input = s + DateTimeStringInputSize <= buf.buffer().end();
    if (optimistic_path_for_date_time_input)
    {
        if (s[4] < '0' || s[4] > '9')
        {
            UInt16 year = (s[0] - '0') * 1000 + (s[1] - '0') * 100 + (s[2] - '0') * 10 + (s[3] - '0');
            UInt8 month = (s[5] - '0') * 10 + (s[6] - '0');
            UInt8 day = (s[8] - '0') * 10 + (s[9] - '0');
            UInt8 hour = (s[11] - '0') * 10 + (s[12] - '0');
            UInt8 minute = (s[14] - '0') * 10 + (s[15] - '0');
            UInt8 second = (s[17] - '0') * 10 + (s[18] - '0');
            if (unlikely(year == 0))