Friday, 13 April 2018

Responsibilities of buffer manager in dbms

Responsibilities of buffer manager in dbms

Buffer manager

The buffer manager is an important part of the database system. The data that are stored and to be handled may be larger than the memory available. In such situations, it is the job of buffer manager to handle it efficiently.

It is sometimes referred as cache manager.

Responsibilities/roles of Buffer Manager


  • Handles all requests for database blocks.
  • Reads data from disk pages (hard disk) into main memory (RAM) whenever needed.
    • If the data already exist in main memory, then buffer manager passes the address in main memory to the requestor.
    • If not, then fetch the data from hard disk to main memory and pass the address in memory to the requestor.
  • It decides which data to be cached in main memory.

The buffer manager has to use the following techniques to deliver its responsibilities efficiently;

  • Replacement strategy – to create room for new data blocks from disk pages
  • Pinned blocks – to recover database from crashes
  • Forced output of blocks – to write forcefully back to disk as required

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Define buffer manager
what are the roles and responsibilities of buffer manager
what is cache manager
the techniques used by buffer manager to handle data efficiently
define buffer manager in dbms
define data manager in dbms




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