ACM SIGMOD is pleased to present the 2015 SIGMOD Jim Gray Doctoral Dissertation Award to Alexander Thomson. Thomson completed his dissertation titled “Deterministic Transaction Execution in Distributed Database Systems” at Yale University under the supervision of Daniel Abadi. The thesis provides a novel system architecture to address a challenging problem in distributed database systems, namely providing scalable support for transactions. The thesis proposes an interesting and surprisingly simple idea: choose the serialization order of transactions up front, and execute the transactions deterministically according to this order. Deterministic execution reduces the amount of coordination required for distributed transactions, which significantly improves scalability. Thomson develops this idea into a complete system and shows that it is remarkably effective for distributed databases and also for file systems. The work is innovative and combines sound principles with solid design and implementation, resulting in a thesis that has already made its mark on the database community.

Alexander ThomsonAlexander Thomson is a software engineer at Google, where he works on storage systems.




ACM SIGMOD is also pleased to recognize Marina Drosou and Karthik Ramachandra for Honorable Mention for the 2015 SIGMOD Jim Gray Doctoral Dissertation Award. Marina completed her dissertation titled “Relevance and Diversity-based Ranking in Network-Centric Information Management Systems” at University of Ioannina under the supervision of Evaggelia Pitoura. Karthik’s thesis is titled “Holistic Optimization of Database Applications” and the PhD was awarded by the IIT Bombay under the supervision of S. Sudarshan.

Marina DrosouMarina Drosou holds a PhD from the Computer Science & Engineering Department of the University of Ioannina and BSc and MSc degrees from the Computer Science Department of the University of Ioannina. Her research interests include personalization via ranking based on diversity and recommendation systems. In the past, she has worked as an Instructor at the Department of Informatics and Telecommunications of the Technological Educational Institute of Epirus, Greece, and was also a visiting trainee researcher at the School of Information Technology and Electrical Engineering of the University of Queensland, Australia. She is currently a software engineer at the Information Systems Division of the Hellenic Police Headquarters. She has received scholarships from the Bodossaki Foundation and the Greek state (“Heraclitus II”). She is the recipient of the VLDB 2013 Best Paper Award. Her work has been published in TODS, VLDBJ, TKDE, PVLDB, etc.

Karthik RamachandraKarthik Ramachandra is currently a Research SDE at the Microsoft Jim Gray Systems Lab. He received his Ph.D. in Computer Science from IIT Bombay, India, advised by Prof. S. Sudarshan.  Karthik’s dissertation, titled “Holistic Optimization of Database Applications”, focuses on improving performance of database applications using techniques that span the boundaries of a traditional program compiler and a database query optimizer. It demonstrates that a combined holistic analysis of the program and its embedded queries opens up many hidden opportunities to optimize database applications. The thesis presents novel holistic techniques that automatically transform programs and queries to perform asynchronous prefetching and batching of queries in applications in order to optimize data access. It also presents a technique for optimization of user-defined functions in SQL queries. The thesis investigates practical issues that are of organic relevance to current database applications, and addresses these problems in a conceptually principled and technically novel manner. The application of programming language technologies towards optimizing database execution strategies, synergistically bringing together largely disparate streams of research activity, forms the core of this thesis.