```
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] [                                                                                                                                                                                                                                        <=>               ]
```

buffer.reserve(result_batch.size());
        for (const auto & row : result_batch)
        {
            String key = row.GetKey();
            if (re2::RE2::FullMatch(key, *matcher))
                buffer.emplace_back(std::move(key));
        }
        
        buffer_iter = buffer.begin();
        request.SetContinuationToken(outcome.GetResult().GetNextContinuationToken());
        
        is_finished = !outcome.GetResult().GetIsTruncated();
    }
    std::mutex mutex;
    Strings buffer;
    Strings::iterator buffer_iter;
    Aws::S3::S3Client client;
    S3::URI globbed_uri;
    Aws::S3::Model::ListObjectsV2Request request;
    Aws::S3::Model::ListObjectsV2Outcome outcome;
    std::unique_ptr<re2::RE2> matcher;
    bool is_finished{false};
};
StorageS3Source::DisclosedGlobIterator::DisclosedGlobIterator(Aws::S3::S3Client & client_, const S3::URI & globbed_uri_)
    : pimpl(std::make_shared<StorageS3Source::DisclosedGlobIterator::Impl>(client_, globbed_uri_)) {}
String StorageS3Source::DisclosedGlobIterator::next()
{
    return pimpl->next();
}
class StorageS3Source::KeysIterator::Impl