DBMS vs. OS File System
OS does disk space & buffer mgmt: why not let OS manage these tasks?
Differences in OS support: portability issues
Some limitations, e.g., files can’t span disks.
Buffer management in DBMS requires ability to:
- pin a page in buffer pool, force a page to disk (important for implementing CC & recovery),
- adjust replacement policy, and pre-fetch pages based on access patterns in typical DB operations.