Using semijoin programs to solve traversal queries in graph databases.

ABSTRACTGraph data processing is gaining popularity and new solutions are appearing to analyze graphs efficiently. In this paper, we present the prototype for the new query engine of the Sparksee graph database, which is based on an algebra of operations on sets of key-value pairs. The new engine combines some regular relational database operations with some extensions oriented to collection processing and complex graph queries. We study the query plans of graph queries expressed in the new algebra, and find that most graph operations can be efficiently expressed as semijoin programs.