越來越多人使用區塊鍊的技術(Fintech 的核心)在不同的領域上，但是現有區塊鍊的查詢功能和支援區塊鍊查詢的工具都還是提供非常有限的查詢方法，而且查詢的反應時間很長。為了解決這些的問題，我們提出HyperQL，他是在Hyperledger Fabric區塊鍊上面增加了一個查詢層，使用區塊監聽器來監聽有沒有生成的區塊，並且得到區塊裡的資料，經過處理器壓縮區塊內的資料，HyperQL 會將數據儲存在PostgreSQL 的資料庫(NewSQL 資料庫系統)中，HyperQL 提供一個簡單的介面來方便查詢。HyperQL可以提供完整的SQL 的指令和良好的性能。在論文中的實驗結果顯示，HyperQL 所提供的查詢指令都具有非常優異的性能表現。

We can envision that the blockchain technology, the core of FinTech, will be adopted for more and more applications in the future. However, the existing blockchain implementation supports very limited query operations and the response time of the supported operations grows with the number of blocks. To address these issues, we propose HyperQL, which is an query layer on the top of the blockchain in Hyperledger Fabric. The HyperQL-enabled Hyperledger Fabric uses the block listener to monitor the response message of generated blocks in real-time. After the handler filters useless data, HyperQL stores the data and updates entries in
PostgreSQL, a NewSQL database system. An interface is provided for users to query the HyperQL-enabled Hyperledger Fabric. The proposed HyperQL-enabled Hyperledger Fabric supports full SQL operations with high performance and reliability. The experiment results show that the excellent performance of important query operations and all advanced query types in the HyperQL-enabled Hyperledger Fabric.

[1] The code from hyperledger fabric github. https://github.com/hyperledger/fabric/tree/master/examples/events/block-listener.
[2] Go programming language. https://golang.org/.
[3] Hyperledger composer. https://hyperledger.github.io/composer/latest/index.html.
[4] Mongodb. https://www.mongodb.com/.
[5] Postgresql. https://www.postgresql.org/.
[6] Olivier Alphand, Michele Amoretti, Timothy Claeys, Simone Dall'Asta, Andrzej Duda, Gianluigi Ferrari, Franck Rousseau, Bernard Tourancheau, Luca Veltri, and Francesco Zanichelli. Iotchain: A blockchain security architecture for the internet of things. In Wireless Communications and Networking Conference (WCNC), 2018 IEEE, pages 1-6. IEEE, 2018.
[7] Vandana Bhagat and Arpita Gopal. Comparative study of row and column oriented database. In Emerging Trends in Engineering and Technology (ICETET), 2012 Fifth International Conference on, pages 196-201. IEEE, 2012.
[8] Andrew D. Birrell and Bruce Jay Nelson. Implementing remote procedure calls. ACM Trans. Comput. Syst., 2(1):39-59, February 1984.
[9] Vitalik Buterin et al. Ethereum white paper. GitHub repository, 2013.
[10] Christian Cachin. Architecture of the hyperledger blockchain fabric. In Workshop on Distributed Cryptocurrencies and Consensus Ledgers, 2016.
[11] Miguel Castro and Barbara Liskov. Practical byzantine fault tolerance and proactive recovery. ACM Transactions on Computer Systems (TOCS), 20(4):398-461, 2002.
[12] Donald D Chamberlin. Relational data-base management systems. ACM Computing Surveys (CSUR), 8(1):43-66, 1976.
[13] Edgar F Codd. A relational model of data for large shared data banks. Communications of the ACM, 13(6):377-387, 1970.
[14] Tim Dierks. The transport layer security (tls) protocol version 1.2. 2008.
[15] Ali Dorri, Marco Steger, Salil S Kanhere, and Raja Jurdak. Blockchain: A distributed solution to automotive security and privacy. IEEE Communications Magazine, 55(12):119-125, 2017.
[16] Arthur Gervais, Srdjan Capkun, Ghassan O Karame, and Damian Gruber. On the privacy provisions of bloom filters in lightweight bitcoin clients. In Proceedings of the 30th Annual Computer Security Applications Conference, pages 326-335. ACM, 2014.
[17] Jing Han, E Haihong, Guan Le, and Jian Du. Survey on nosql database. In Pervasive computing and applications (ICPCA), 2011 6th international conference on, pages 363-366. IEEE, 2011.
[18] Markus Jakobsson, Tom Leighton, Silvio Micali, and Michael Szydlo. Fractal merkle tree representation and traversal. In Cryptographers Track at the RSA Conference, pages 314-326. Springer, 2003.
[19] J. Jiang. Implementing the patricia data structure for compression algorithms with finite size dictionaries. In 1992 International Conference on Data Transmission Advances in Modem and ISDN Technology and Applications, pages 123-127, Sep 1992.
[20] Sunny King and Scott Nadal. Ppcoin: Peer-to-peer crypto-currency with proof-of-stake. self-published paper, August, 19, 2012.
[21] Kenneth P Laberteaux, Jason J Haas, and Yih-Chun Hu. Security certi_cate revocation list distribution for vanet. In Proceedings of the fifth ACM international
workshop on VehiculAr Inter-NETworking, pages 88-89. ACM, 2008.
[22] Leslie Lamport, Robert Shostak, and Marshall Pease. The byzantine generals problem. ACM Transactions on Programming Languages and Systems (TOPLAS), 4(3):382-401, 1982.
[23] Yang Li, Kai Zheng, Ying Yan, Qi Liu, and Xiaofang Zhou. Etherql: A query layer for blockchain system. In International Conference on Database Systems for Advanced Applications, pages 556-567. Springer, 2017.
[24] Ricardo Macedo, João Paulo, Rogério Pontes, Bernardo Portela, Tiago Oliveira, Miguel Matos, and Rui Oliveira. A practical framework for privacy-preserving nosql databases. In Reliable Distributed Systems (SRDS), 2017 IEEE 36th Symposium on, pages 11-20. IEEE, 2017.
[25] ABM Moniruzzaman. Newsql: Towards next-generation scalable rdbms for online transaction processing (oltp) for big data management. arXiv preprint arXiv:1411.7343, 2014.
[26] Mayank Raikwar, Subhra Mazumdar, Sushmita Ruj, Sourav Sen Gupta, Anupam Chattopadhyay, and Kwok-Yan Lam. A blockchain framework for insurance processes. In New Technologies, Mobility and Security (NTMS), 2018 9th IFIP International Conference on, pages 1-4. IEEE, 2018.
[27] Alex Rodriguez. Restful web services: The basics. IBM developerWorks, page 33, 2008.
[28] J.D Sanjay Ghemawat. Leveldb github page. https://github.com/google/leveldb.
[29] Pradeep K. Sinha. Remote Procedure Calls, pages 764-. Wiley-IEEE Press, 1997.
[30] Julian Skan, James Dickerson, and Samad Masood. The future of fintech and banking: Digitally disrupted or reimagined. Accenture, London, 2015.
[31] Matthew D Sleiman, Adrian P Lauf, and Roman Yampolskiy. Bitcoin message: Data insertion on a proof-of-work cryptocurrency system. In Cyberworlds (CW), 2015 International Conference on, pages 332-336. IEEE, 2015.
[32] Michael Stonebraker. Newsql: An alternative to nosql and old sql for new oltp apps. Communications of the ACM. Retrieved, pages 07-06, 2012.
[33] H. Sukhwani, J. M. Martnez, X. Chang, K. S. Trivedi, and A. Rindos. Performance modeling of pbft consensus process for permissioned blockchain network (hyperledger fabric). In 2017 IEEE 36th Symposium on Reliable Distributed Systems (SRDS), pages 253-255, Sept 2017.
[34] Seema Sultana and Sunanda Dixit. Indexes in postgresql. In Innovative Mechanisms for Industry Applications (ICIMIA), 2017 International Conference on, pages 512-515. IEEE, 2017.
[35] Tim Swanson. Consensus-as-a-service: a brief report on the emergence of permissioned, distributed ledger systems. Report, available online, Apr, 2015.
[36] Jinesh Varia and Sajee Mathew. Overview of amazon web services. Amazon Web Services, 2014.
[37] D. Vujii, D. Jagodi, and S. Rani. Blockchain technology, bitcoin, and ethereum: A brief overview. In 2018 17th International Symposium INFOTEH-JAHORINA (INFOTEH), pages 1-6, March 2018.
[38] Dan Williams and Emin Gun Sirer. Optimal parameter selection for e_cient memory integrity veri_cation using merkle hash trees. In Network Computing and Applications, 2004.(NCA 2004). Proceedings. Third IEEE International Symposium on, pages 383-388. IEEE, 2004.
[39] M. Wohrer and U. Zdun. Smart contracts: security patterns in the ethereum ecosystem and solidity. In 2018 International Workshop on Blockchain Oriented Software Engineering (IWBOSE), pages 2-8, March 2018.
[40] Gavin Wood. Ethereum: A secure decentralised generalised transaction ledger. Ethereum Project Yellow Paper, 151:1-32, 2014.
[41] Yuqin Xu, Shangli Zhao, Lanju Kong, Yongqing Zheng, Shidong Zhang, and Qingzhong Li. Ecbc: A high performance educational certi_cate blockchain with efficient query. In International Colloquium on Theoretical Aspects of Computing, pages 288-304. Springer, 2017.
[42] Peng Zhang, Jules White, Douglas C Schmidt, Gunther Lenz, and S Trent Rosenbloom. Fhirchain: Applying blockchain to securely and scalably share clinical data. arXiv preprint arXiv:1807.03227, 2018.