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

client_auth.client,
            client_auth.uri.bucket,
            keys.back(),
            min_upload_part_size,
            max_single_part_upload_size);
    }
}
void StorageS3::truncate(const ASTPtr & , const StorageMetadataPtr &, ContextPtr local_context, TableExclusiveLockHolder &)
{
    updateClientAndAuthSettings(local_context, client_auth);
    if (is_key_with_globs)
        throw Exception(ErrorCodes::DATABASE_ACCESS_DENIED, "S3 key '{}' contains globs, so the table is in readonly mode", client_auth.uri.key);
    Aws::S3::Model::Delete delkeys;
    for (const auto & key : keys)
    {
        Aws::S3::Model::ObjectIdentifier obj;
        obj.SetKey(key);
        delkeys.AddObjects(std::move(obj));
    }
    Aws::S3::Model::DeleteObjectsRequest request;
    request.SetBucket(client_auth.uri.bucket);
    request.SetDelete(delkeys);
    auto response = client_auth.client->DeleteObjects(request);
    if (!response.IsSuccess())
    {
        const auto & err = response.GetError();
        throw Exception(std::to_string(static_cast<int>(err.GetErrorType())) + ": " + err.GetMessage(), ErrorCodes::S3_ERROR);
    }
}
void StorageS3::updateClientAndAuthSettings(ContextPtr ctx, StorageS3::ClientAuthentication & upd)