- Full RMDB framework from upstream
- DiskManager: create_file, open_file, close_file, destroy_file, write_page, read_page
- LRUReplacer: victim, pin, unpin (LRU淘汰策略)
- BufferPoolManager: new_page, fetch_page, find_victim_page, update_page, unpin_page, delete_page, flush_page, flush_all_pages
- RmFileHandle: get_record, insert_record(x2), delete_record, update_record + 辅助函数
- RmScan: 构造函数, next, is_end