Cquirrel: continuous query processing over acyclic relational schemas

Qichen Wang, Chaoqi Zhang, Danish Alsayed, Ke Yi, Bin Wu, Feifei Li, Chaoqun Zhan

Research output: Contribution to journalConference articlepeer-review


We will demonstrate Cquirrel, a continuous query processing engine built on top of Flink. Cquirrel assumes a relational schema where the foreign-key constraints form a directed acyclic graph, and supports any selection-projection-join-aggregation query where all join conditions are between a primary key and a foreign key. It allows arbitrary updates to any of the relations, and outputs the deltas in the query answers in real-time. It provides much better support for multi-way joins than the native join operator in Flink. Meanwhile, it offers better performance, scalability, and fault tolerance than other continuous query processing engines.

Original languageEnglish
Pages (from-to)2667-2670
Number of pages4
JournalProceedings of the VLDB Endowment
Issue number12
Publication statusPublished - Jul 2021
Event47th International Conference on Very Large Data Bases, VLDB 2021 - Virtual, Online
Duration: 16 Aug 202120 Aug 2021

Scopus Subject Areas

  • Computer Science (miscellaneous)
  • Computer Science(all)


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