Issue 2 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 October 2020: - Tsunami: A Learned Multi-dimensional Index for Correlated Data and Skewed Workloads Jialin Ding, Vikram Nathan, Mohammad Alizadeh, Tim Kraska http://www.vldb.org/pvldb/vol14/p74-ding.pdf - Jointly Optimizing Preprocessing and Inference for DNN-based Visual Analytics Daniel Kang, Ankit Mathur, Teja Veeramacheneni, Peter Bailis, Matei Zaharia http://www.vldb.org/pvldb/vol14/p87-kang.pdf - Permutable Compiled Queries: Dynamically Adapting Compiled Queries without Recompiling Prashanth Menon, Amadou Ngom, Todd Mowry, Andrew Pavlo, Lin Ma http://www.vldb.org/pvldb/vol14/p101-menon.pdf - EMOGI: Efficient Memory-access for Out-of-memory Graph-traversal In GPUs Seung Won Min, Vikram Sharma Mailthody, Zaid Qureshi, Jinjun Xiong, Eiman Ebrahimi, Wen-Mei Hwu http://www.vldb.org/pvldb/vol14/p114-min.pdf - On-Off Sketch: A Fast and Accurate Sketch on Persistence Yinda Zhang, Jinyang Li, Yutian Lei, Tong Yang, Zhetao Li, Gong Zhang, Bin Cui http://www.vldb.org/pvldb/vol14/p128-zhang.pdf - Real-Time Distance-Based Outlier Detection in Data Streams Luan Tran, Min Mun, Cyrus Shahabi http://www.vldb.org/pvldb/vol14/p141-tran.pdf - Seagull: An Infrastructure for Load Prediction and Optimized Resource Allocation Olga Poppe, Tayo Amuneke, Dalitso Banda, Aritra De, Ari Green, Manon Knoertzer, Ehi Nosakhare, Karthik Rajendran, Deepak Shankargouda, Meina Wang, Alan Au, Carlo Curino, Qun Guo, Alekh Jindal, Ajay Kalhan, Morgan Oslake, Sonia Parchani, Vijay Ramani, Raj Sellappan, Saikat Sen, Sheetal Shrotri, Soundararajan Srinivasan, Ping Xia, Shize Xu, Alicia Yang, Yiwen Zhu http://www.vldb.org/pvldb/vol14/p154-poppe.pdf - On the Efficiency of K-Means Clustering: Evaluation, Optimization, and Algorithm Selection Sheng Wang, Yuan Sun, Zhifeng Bao http://www.vldb.org/pvldb/vol14/p163-wang.pdf - RapidMatch: A Holistic Approach to Subgraph Query Processing Shixuan Sun, Xibo Sun, Yulin Che, Qiong Luo, Bingsheng He http://www.vldb.org/pvldb/vol14/p176-sun.pdf - Taurus: Lightweight Parallel Logging for In-Memory Database Management Systems Yu Xia, Xiangyao Yu, Andrew Pavlo, Srinivas Devadas http://www.vldb.org/pvldb/vol14/p189-xia.pdf - Improving Execution Efficiency of Just-in-time Compilation based Query Processing on GPUs Johns Paul, Bingsheng He, Shengliang Lu, Chiew Tong Lau http://www.vldb.org/pvldb/vol14/p202-paul.pdf - PPQ-Trajectory: Spatio-temporal Qantization for Qerying in Large Trajectory Repositories Shuang Wang, Hakan Ferhatosmanoglu http://www.vldb.org/pvldb/vol14/p215-wang.pdf - Aggregated Deletion Propagation for Counting Conjunctive Query Answers Xiao Hu, Shouzhuo Sun, Shweta Patwa, Debmalya Panigrahi, Sudeepa Roy http://www.vldb.org/pvldb/vol14/p228-hu.pdf Best regards, Thorsten Papenbrock, HPI, Germany Hannes Muehleisen, CWI, The Netherlands VLDB 2021 Proceedings Chairs