```
ubuntu@ip-172-31-79-147:/opt/downloads$ clickhouse-local --max_threads 8 --query "WITH parseDateTimeBestEffort(extract(_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, (values[3])::UInt64 AS hits FROM file('pageviews*.gz', LineAsString) WHERE length(values) >= 3" | pv > /dev/null
^C01GiB 0:01:08 [ 129MiB/s] [                                                                                                                                                                   <=>                                                                                    ]

ubuntu@ip-172-31-79-147:/opt/downloads$ clickhouse-local --max_threads 8 --query "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, (values[3])::UInt64 AS hits FROM file('pageviews*.gz', LineAsString) WHERE length(values) >= 3" | pv > /dev/null
^C46GiB 0:00:48 [ 175MiB/s] [                                                                                                                                                                                                                                        <=>               ]
```

{
    if (!reader)
        return {};
    Chunk chunk;
    if (reader->pull(chunk))
    {
        UInt64 num_rows = chunk.getNumRows();
        if (with_path_column)
            chunk.addColumn(DataTypeString().createColumnConst(num_rows, file_path)->convertToFullColumnIfConst());
        if (with_file_column)
        {
            size_t last_slash_pos = file_path.find_last_of('/');
            chunk.addColumn(DataTypeString().createColumnConst(num_rows, file_path.substr(
                    last_slash_pos + 1))->convertToFullColumnIfConst());
        }
        return chunk;
    }
    {
        std::lock_guard lock(reader_mutex);
        reader.reset();
        pipeline.reset();
        read_buf.reset();
        if (!initialize())
            return {};
    }
    return generate();
}
static bool checkIfObjectExists(const std::shared_ptr<Aws::S3::S3Client> & client, const String & bucket, const String & key)