Implementation of buffering
Buffering is a technique used to programmers, programming languages, and operating systems to reduce the number of disk access.
- Programming languages
- Java’s
BufferedInputStream
- Python I/O implemented with buffered streams
- Java’s
- Operating systems
- MVS JCL
RECFM=FB
- Linux buffer cache
- MVS JCL
- Oracle buffer cache (See Lee Johnson)
Expected access time
What is the average time required to perform a read request?
- 99% of the time a read request is found in the “buffer” and retrieved in 1 µsec.
- 1% of the time a read request must be retrieved from disk which requires in 20 msec.