Understanding Queries by Conditional Instances

Explore a 29-minute lecture by Sudeepa Roy from Duke University on understanding queries through conditional instances. Delve into the challenge of providing simple, generic "representative" instances that illustrate query satisfaction and summarize specific instances. Investigate the possibility of finding a collection of such instances to characterize all ways a query can be satisfied. Learn about the design of representative instances, their meaning, and the formalization of query satisfaction. Discover why this problem is undecidable for general domain relational calculus queries. Examine practical algorithms for computing minimum collections of instances under constraints. Review experimental evaluations of the approach's efficiency and its effectiveness in helping users debug relational queries. Based on a SIGMOD'22 paper, this talk offers insights into logic and algebra for query evaluation in the field of relational databases.