A sequential file “properly” stored on an empty disk can be retrieved with minimal seeking. But disks tend to become heavily fragmented as files are added and deleted. Thus, successive references to “adjacent” records in a disk file can result in substantial seeking throughout the disk. Discuss the notion of file reorganization as a scheme for minimizing seeks.Under what circumstances should a file be reorganized?
What will be an ideal response?
Obviously, by reorganizing a sequential file that is fragmented throughout the disk,
retrieval becomes much faster, because sequential file locations are moved to contiguous
physical locations on disk. Files that contain data dispersed throughout secondary storage
should be defragmented so that most or all of a file’s data is physically contiguous. If most of
a file’s data is already contiguous, the overhead incurred by performing defragmentation
might then outweigh the resulting performance improvement.
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