Abstract: Online query processing for large-scale, incremental data analysis on a distributed stream processing engine (DSPE). Our goal is to convert any SQL-like query to an incremental DSPE program automatically. In contrast to other approaches, we derive incremental programs that return accurate results, not approximate answers, by retaining a minimal state during the query evaluation lifetime and by using a novel incremental evaluation technique, which, at each time interval, returns an accurate snapshot answer that depends on the current state and the latest batches of data. Our methods can handle many forms of queries on nested data collections, including iterative and nested queries, group-by with aggregation, and equi-joins. Finally, we report on a prototype implementation of our framework, called MRQL Streaming, running on top of Spark and we experimentally validate the effectiveness of our methods.
Keywords: Outlier detection, Stream data mining, Local outlier, Memory efficiency.