Rethinking Hash Tables: Challenges and Opportunities with Compute Express Link (CXL).

Hash tables can efficiently determine whether an element exists in a given set and have been widely used in computer networks, the Internet of Things (IoT), data centers, and stream data mining. With the continuous generation of massive data, the memory consumption of hash tables keeps increasing. The emerging Compute Express Link (CXL) technique can significantly expand memory capacity. Porting hash tables from DRAM to CXL memory can alleviate the issue that hash tables occupy significant amounts of DRAM space. However, porting hash tables to CXL memory is not a trivial task. This paper analyzes the challenges of porting hash tables to CXL memory and shows opportunities to address these challenges.