- GD2L is a cost-aware buffer pool management algorithm that uses two priority queues to manage pages on SSD vs HDD. CAC is a predictive cost-based technique for managing which pages are placed on SSD. - Experiments show that using GD2L and CAC together provides up to 2x better TPC-C performance compared to LRU baseline, by lowering total I/O costs on both SSD and HDD for large 30GB databases. For