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

}
    else
        storage_metadata.setColumns(columns_);
    storage_metadata.setConstraints(constraints_);
    storage_metadata.setComment(comment);
    setInMemoryMetadata(storage_metadata);
}
ColumnsDescription StorageHDFS::getTableStructureFromData(
    const String & format,
    const String & uri,
    const String & compression_method,
    ContextPtr ctx)
{
    auto read_buffer_creator = [&]()
    {
        const auto [path_from_uri, uri_without_path] = getPathFromUriAndUriWithoutPath(uri);
        auto paths = getPathsList(path_from_uri, uri, ctx);
        if (paths.empty())
            throw Exception(
                ErrorCodes::CANNOT_EXTRACT_TABLE_STRUCTURE,
                "Cannot extract table structure from {} format file, because there are no files in HDFS with provided path. You must "
                "specify table structure manually",
                format);
        auto compression = chooseCompressionMethod(paths[0], compression_method);
        return wrapReadBufferWithCompressionMethod(
            std::make_unique<ReadBufferFromHDFS>(uri_without_path, paths[0], ctx->getGlobalContext()->getConfigRef()), compression);
    };
    return readSchemaFromFormat(format, std::nullopt, read_buffer_creator, ctx);
}
class HDFSSource::DisclosedGlobIterator::Impl