Issue 4 of Volume 14 of the Proceedings of the VLDB Endowment (PVLDB) is now available electronically at the VLDB website: http://www.vldb.org/pvldb/vol14.html This issue consists of the following papers that have been accepted for the research track of VLDB 2021 in Copenhagen, Denmark in December 2020: - Space- and Computationally-Efficient Set Reconciliation via Parity Bitmap Sketch (PBS) Long Gong, Ziheng Liu, Liang Liu, Jun Xu, Mitsunori Ogihara, Tong Yang http://www.vldb.org/pvldb/vol14/p458-gong.pdf - Astrid: Accurate Selectivity Estimation for String Predicates using Deep Learning Suraj Shetiya, Saravanan Thirumuruganathan, Nick Koudas, Gautam Das http://www.vldb.org/pvldb/vol14/p471-shetiya.pdf - Compact, Tamper-Resistant Archival of Fine-Grained Provenance Nan Zheng, Zack Ives http://www.vldb.org/pvldb/vol14/p485-zheng.pdf - Rumble: Data Independence for Large Messy Data Sets Ingo Müller, Ghislain Fourny, Stefan Irimescu, Can Cikis, Gustavo Alonso http://www.vldb.org/pvldb/vol14/p498-müller.pdf - Capturing and querying fine-grained provenance of preprocessing pipelines in data science Adriane Chapman, Paolo Missier, Giulia Simonelli, Riccardo Torlone http://www.vldb.org/pvldb/vol14/p507-chapman.pdf - Local Dampening: Differential Privacy for Non-numeric Queries via Local Sensitivity Victor Farias, Felipe Brito, Cheryl Flynn, Javam Machado, Subhabrata Majumdar, Divesh Srivastava http://www.vldb.org/pvldb/vol14/p521-farias.pdf - Mainlining Databases: Supporting Fast Transactional Workloads on Universal Columnar Data File Formats Tianyu Li, Matthew Butrovich, Amadou Ngom, Wan Shen Lim, Wes Mckinney, Andrew Pavlo http://www.vldb.org/pvldb/vol14/p534-li.pdf - Accelerating Exact Constrained Shortest Paths on GPUs Shengliang Lu, Bingsheng He, Yuchen Li, Hao Fu http://www.vldb.org/pvldb/vol14/p547-lu.pdf - Towards an Efficient Weighted Random Walk Domination Songsong Mo, Zhifeng Bao, Ping Zhang, Zhiyong Peng http://www.vldb.org/pvldb/vol14/p560-mo.pdf - Scalable Mining of Maximal Quasi-Cliques: An Algorithm-System Codesign Approach Guimu Guo, Da Yan, Tamer Özsu, Zhe Jiang, Jalal Khalil http://www.vldb.org/pvldb/vol14/p573-guo.pdf - CALYPSO: Private Data Management for Decentralized Ledgers Eleftherios Kokoris Kogias, Enis Ceyhun Alp, Linus Gasser, Philipp Jovanovic, Ewa Syta, Bryan Ford http://www.vldb.org/pvldb/vol14/p586-kogias.pdf - Stacked Filters: Learning to Filter by Structure Brian Hentschel, Stratos Idreos, Kyle Deeds http://www.vldb.org/pvldb/vol14/p600-hentschel.pdf - Maximizing Social Welfare in a Competitive Diffusion Model Prithu Banerjee, Laks V.s. Lakshmanan, Wei Chen http://www.vldb.org/pvldb/vol14/p613-banerjee.pdf - Understanding the Idiosyncrasies of Real Persistent Memory Shashank Gugnani, Arjun Kashyap, Xiaoyi Lu http://www.vldb.org/pvldb/vol14/p626-gugnani.pdf - Explaining Ranking Functions Amelie Marian, Abraham Gale http://www.vldb.org/pvldb/vol14/p640-marian.pdf - ConnectIt: A Framework for Static and Incremental Parallel Graph Connectivity Algorithms Laxman Dhulipala, Changwan Hong, Julian Shun http://www.vldb.org/pvldb/vol14/p653-dhulipala.pdf - Quality of Sentiment Analysis Tools: The Reasons of Inconsistency Wissam Mammar Kouadri, Mourad Ouziri, Salima Benbernou, Karima Echihabi, Themis Palpanas, Iheb Benamor http://www.vldb.org/pvldb/vol14/p668-kouadri.pdf - Hindsight Logging for Model Training Rolando Garcia, Erick Liu, Vikram Sreekanti, Bobby Yan, Anusha Dandamudi, Joseph Gonzalez, Joseph Hellerstein, Koushik Sen http://www.vldb.org/pvldb/vol14/p682-garcia.pdf - Scalable Structural Index Construction for JSON Analytics Zhijia Zhao, Lin Jiang http://www.vldb.org/pvldb/vol14/p694-zhao.pdf - Efficient Join Algorithms For Large Database Tables in a Multi-GPU Environment Ran Rui, Hao Li, Yi-Cheng Tu http://www.vldb.org/pvldb/vol14/p708-rui.pdf Best regards, Thorsten Papenbrock, HPI, Germany Hannes Muehleisen, CWI, The Netherlands VLDB 2021 Proceedings Chairs