Traditional buffer mapping was designed decades ago and, despite all of the low-level optimizations, it can’t scale on modern hardware. In addition, in-memory engines limit the database size to the size of the main memory. In contrast, OrioleDB’s dual pointer approach allows removing the buffer mapping overhead while saving the ability to automatically evict the least recently used pages from main memory.

PostgreSQL is an excellent DBMS, which has shown to be very scalable over decades. Nonetheless, the traditional buffer mapping design limits PostgreSQL scalability on modern hardware. Thankfully, the OrioleDB engine provides a solution within an extension and minimal patch to the core.