Chases and Bag-Set Certain Answers

TL;DR

This paper demonstrates that the chase technique effectively captures bag-set semantics for conjunctive queries with IDs and TGDs, enabling efficient evaluation and supporting certain aggregate queries under incomplete information.

Contribution

It shows the chase's power in capturing bag-set semantics and provides efficient algorithms, also extending to restricted aggregate query evaluation under incomplete data.

Findings

Chase captures bag-set semantics for conjunctive queries with IDs and TGDs.

Query evaluation can be performed in LogSpace, indicating high efficiency.

Chase can be used as a basis for evaluating some aggregate queries under incomplete information.

Abstract

In this paper we show that the chase technique is powerful enough to capture the bag-set semantics of conjunctive queries over IDBs and IDs and TGDs. In addition, we argue that in such cases it provides efficient (LogSpace) query evaluation algorithms and that, moreover, it can serve as a basis for evaluating some restricted classes of aggregate queries under incomplete information.