Responsibility of the Buffer Manager

It is the responsibility of the buffer manager to allow process to get the pages they need, while minimizing disk accesses and unsatisfied requests. by implementing a page replacement strategy.

The buffer pool is an array of frames containing a page, a dirty bit, the page number, and the pin count for the page occupying that frame. A hash table is used to know what page frame a given disk page (i.e., with a given pageId) occupies. When a page is requested, the buffer manager brings it in and pins it, and implement a page replacement strategy when a free frame is not available for the requested page in the buffer pool. The buffer manager does not keep track of all the pages that have been pinned by a transaction. It is up to the various components (that call the buffer manager) to make sure that all pinned pages are subsequently unpinned.

The Buffer Manager is used by the other modules to read / write / allocate / de-allocate pages. The Buffer Manager makes calls to the underlying Permanent Memory Manager, which actually performs these operations on disk pages.

role of buffer manager in dbms,

if the data is not in the buffer pool the buffer manager calls,

minibase buffer manager,

file manager in dbms,

disk space manager in dbms,