**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.
{
    assertString(s.c_str(), buf);
}
bool checkString(const char * s, ReadBuffer & buf);
inline bool checkString(const String & s, ReadBuffer & buf)
{
    return checkString(s.c_str(), buf);
}
bool checkStringCaseInsensitive(const char * s, ReadBuffer & buf);
inline bool checkStringCaseInsensitive(const String & s, ReadBuffer & buf)
{
    return checkStringCaseInsensitive(s.c_str(), buf);
}
void assertStringCaseInsensitive(const char * s, ReadBuffer & buf);
inline void assertStringCaseInsensitive(const String & s, ReadBuffer & buf)
{
    return assertStringCaseInsensitive(s.c_str(), buf);
}
/** Check that next character in buf matches first character of s.
  * If true, then check all characters in s and throw exception if it doesn't match.
  * If false, then return false, and leave position in buffer unchanged.
  */
bool checkStringByFirstCharacterAndAssertTheRest(const char * s, ReadBuffer & buf);
bool checkStringByFirstCharacterAndAssertTheRestCaseInsensitive(const char * s, ReadBuffer & buf);
inline bool checkStringByFirstCharacterAndAssertTheRest(const String & s, ReadBuffer & buf)