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

{
public:
    using FileFormat = StorageHive::FileFormat;
    struct SourcesInfo
    {
        HiveMetastoreClientPtr hive_metastore_client;
        std::string database;
        std::string table_name;
        HiveFiles hive_files;
        NamesAndTypesList partition_name_types;
        std::atomic<size_t> next_uri_to_read = 0;
        bool need_path_column = false;
        bool need_file_column = false;
    };
    using SourcesInfoPtr = std::shared_ptr<SourcesInfo>;
    static Block getHeader(Block header, const SourcesInfoPtr & source_info)
    {
        if (source_info->need_path_column)
            header.insert({DataTypeString().createColumn(), std::make_shared<DataTypeString>(), "_path"});
        if (source_info->need_file_column)
            header.insert({DataTypeString().createColumn(), std::make_shared<DataTypeString>(), "_file"});
        return header;
    }
    static ColumnsDescription getColumnsDescription(Block header, const SourcesInfoPtr & source_info)