  JIT (Just-in-Time) technology has garnered significant attention for
improving the efficiency of database execution. It offers higher performance by
eliminating interpretation overhead compared to traditional execution engines.
LLVM serves as the primary JIT architecture, which was implemented in
PostgreSQL since version 11. However, recent advancements in WASM-based
databases, such as Mutable, present an alternative JIT approach. This approach
minimizes the extensive engineering efforts associated with the execution
engine and focuses on optimizing supported operators for lower latency and
higher throughput. In this paper, we perform comprehensive experiments on these
two representative open-source databases to gain deeper insights into the
effectiveness of different JIT architectures.
