Memory Management in Complex Join Queries: A Re-evaluation Study

Efficient multi-join query processing is crucial but remains a complex, ongoing challenge for high-performance data management systems (DBMSs). This paper studies the impact of different memory distribution techniques among join operators on different classes of multi-join query plans under different assumptions regarding memory availability and storage devices such as HDD and SSD on Amazon Web Services (AWS). We re-evaluate the results of one of the early impactful studies from the 1990s that was originally done using a simulator for the Gamma database system. The main goal of our study is to scientifically re-evaluate and build upon previous studies whose results have become the basis for the design of past and modern database systems, and to provide a solid foundation for understanding basic "join physics", which is essential for eventually designing a resource-based scheduler for concurrent complex workloads.