PIE: Approximate interleaving event matching over sequences

Most of the recent complex event semantics is based on regular expressions, extended with additional filters such as window constraints. We observe that many applications today require parallel (interleaving) event patterns. Moreover, we observe that this matching needs to be approximate in terms of event orders and missing events. We first propose the query semantics. Then we devise a foundation algorithm, on top of which two optimization techniques are proposed. Finally, we perform a comprehensive experimental evaluation using three real-world datasets in different domains and synthetic datasets.