4 papers
Towards Output-Optimal Uniform Sampling and Approximate Counting for Join-Project Queries
Xiao Hu, Jinchao Huang
Uniform sampling and approximate counting are fundamental primitives for modern database applications, ranging from query optimization to approximate query processing. While recent…
Subset Sampling over Joins
Aryan Esmailpour, Xiao Hu, Jinchao Huang +1
Subset sampling (also known as Poisson sampling), where the decision to include any specific element in the sample is made independently of all others, is a fundamental primitive i…
Space-Time Tradeoffs for Spatial Conjunctive Queries
Aryan Esmailpour, Xiao Hu, Stavros Sintos
Given a conjunctive query and a database instance, we aim to develop an index that can efficiently answer spatial queries on the results of a conjunctive query. We are interested i…
Finding Smallest Witnesses for Conjunctive Queries
Xiao Hu, Stavros Sintos
A witness is a sub-database that preserves the query results of the original database but of much smaller size. It has wide applications in query rewriting and debugging, query exp…