This query does not show realtime metrics:

```
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
```

Although this query does:

```
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
```

I also was not able to cancel the first query.
{
    return "HDFSSource";
}
Chunk HDFSSource::generate()
{
    if (!reader)
        return {};
    Chunk chunk;
    if (reader->pull(chunk))
    {
        Columns columns = chunk.getColumns();
        UInt64 num_rows = chunk.getNumRows();
        
        if (need_path_column)
        {
            auto column = DataTypeLowCardinality{std::make_shared<DataTypeString>()}.createColumnConst(num_rows, current_path);
            columns.push_back(column->convertToFullColumnIfConst());
        }
        if (need_file_column)
        {
            size_t last_slash_pos = current_path.find_last_of('/');