Thursday, 15 December 2016

Database buffer cache and its role in DBMS

Buffer Cache in DBMS / How buffer cache used in DBMS? / What is the role of buffer cache in handling transactions faster? / Define database buffer cache


Buffer Cache

Buffer Cache is a shared and reserved memory area that stores the most recently accessed data blocks from hard disk in RAM. It is also called as data cache. It may contain “dirty” (modified data blocks) and “clean” (unused) blocks. Buffer cache is mainly used to take advantage of a computer’s fast primary memory compared to the slower secondary memory, thereby minimizing the number of input/output (I/O) operations between the primary and secondary memories.
For example, when you execute a query to find some information the DBMS will fetch the data blocks that might contain the required records into buffer cache. Then the data blocks in the buffer cache will be searched for the required records.

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