Manages buffer pool: the pool provides space for a limited
number of pages from disk.
Needs to decide on page replacement policy.
Enables the higher levels of the DBMS to assume that the
needed data is in main memory.
Why not use the Operating System for the task??
- DBMS may be able to anticipate access patterns
- Hence, may also be able to perform prefetching
- DBMS needs the ability to force pages to disk.