报告摘要：The diversity and complexity of modern data management applications have led to the extension of the relational paradigm with syntactic and semantic support for User-Defined Functions (UDFs). Although well-established in traditional DBMS settings, UDFs have become central in many application contexts as well, such as data science, data analytics, and edge computing. Still, a critical limitation of UDFs is the impedance mismatch between their evaluation and relational processing.

In this talk, I will first give an overview of the area and the technical challenges that UDF processing brings. I will then present YeSQL, an SQL extension with rich UDF support along with a pluggable architecture to easily integrate it with either server-based or embedded database engines. YeSQL currently supports Python UDFs fully integrated with relational queries as scalar, aggregator, or table functions. Key novel characteristics of YeSQL include easy implementation of complex algorithms and several performance enhancements, including tracing JIT compilation of Python UDFs, parallelism and fusion of UDFs, stateful UDFs, and seamless integration with a database engine. Experimental analysis showcases the usability and expressiveness of YeSQL and demonstrates that its techniques of minimizing context switching between the relational engine and the Python VM are very effective and achieve significant speedups of up to 68x in common, practical use cases compared to earlier approaches and alternative implementation choices.

个人简介：Yannis Ioannidis (Ph.D., Computer Sciences, UC Berkeley; MSc, Applied Mathematics, Harvard University; Diploma, Electrical Engineering, National Technical University of Athens) is the President of theAssociation of Computing Machinery (ACM). He is a Professor at the Department of Informatics and Telecommunications of the National and Kapodistrian University of Athens as well as an Associated Faculty at the “Athena” Research and Innovation Center, where he also served as the President and GeneralDirector for 10 years. His research interests include Database and Information Systems, Data Science, Data and Text Analytics, Data Infrastructures and Digital Repositories, Recommender Systems and Personalization, and Human-Computer Interaction, topics on which he has published over 170 articles in leading journals and conferences and also holds four patents. His work is often inspired by and applied to data management and analysis problems that arise in industrial environments or in the context of other scientific fields (Social Sciences and Humanities, Life Sciences, Physical Sciences) and the Arts. He has been the coordinator and legal entity head of OpenAIRE, which implements the European policies on open access to research publications and data. He is the software director of the European Human Brain Project flagship initiative, the coordinator of the EOSC Future strategic project, which implements the core elements of the European Open Science Cloud, and a coordinator or partner in tens of other European and national research and innovation projects. He has also led or is currently leading the creation of new international or spin-off companies. He is an ACM and IEEE Fellow, a member of Academia Europaea, and a recipient of several research and teaching awards. He is currently the Greek delegate to the European Strategy Forum on Research Infrastructures (ESFRI) and a co-chair of the Global Climate Hub of the UN Sustainable Development Solutions Network.