BIFOLD Colloquium - A Brief history of Continuous Querying

BIFOLD Data Systems Colloquium: "A brief history of Continuous Querying"

Speaker: Riccardo Tommasini, INSA Lyon

Abstract: Continuous queries, also known as standing or streaming queries, are a class of queries that continuously monitor data sources over time, remaining active until explicitly terminated. This concept was introduced in 1992 by Terry and colleagues to address the need to access data that changes over time.
Since then, the domain of continuous queries has seen significant development, research, and application in various data systems, including multiple Database Management Systems (DBMS). Notably, the past five years have marked the rise of Streaming Databases (SDS), like RisingWave and Materialize, 
and DBMSs that integrate continuous queries with traditional query responses., such as Firebase, Meteor, and InvaliDB.  This growth reflects both industrial and academic interest in the field. While initially ccontinuous queries were  focused on the relational model, with their semantics expressed through extended algebras, calculi, or denotational semantics. However, more recently, there has been a shift towards applying continuous queries in the context of connected data. This includes exploration and abstraction in Graph DBMS, Knowledge Graphs, and Knowledge Evolution, expanding beyond the initial focus on relational models. This talk delves into the concept of Continuous Queries in past and modern data systems. In addition to the historical perspective, the talk will focus on the latest developments in Streaming Databases and the continuous processing of streaming graphs.

Bio: Riccardo Tommasini is a Maître de conférence (Associate Professor) at INSA Lyon, LIRIS Lab and a Visiting Professor at the University of Tartu, Estonia. Riccardo holds a Ph.D. from the Department of Electronics and Information of the Politecnico di Milano. His thesis, titled *Velocity on the Web*, investigates the velocity aspects that concern the Web environment. His research interests span Stream Processing, Knowledge Graphs, Database System Internals, Logics and Reasoning, and Programming Languages. His Research has been recently founded by the French National Research Agency ANR. Since 2015, Riccardo has been attending and speaking at international events both in academia (ISWC, ESWC, WWW, DEBS, EDBT) and industry (DockerCon, InfluxDays, LinuxLab, Digit). He also spoke a numerous meetups like the Time Series Meetup Tallin (200+ attendants), Kafka Meetup Milan (60+ attendants), and Data Science Seminars Tartu (200+ online attendants).