Basic Consistency Algorithm
The algorithm for providing view consistency requires
tracking of the last version of each file or directory that has been
accessed.
- On each file operation,
the last recorded version is used to obtain file replicas
that have the same version
or a later version
of the data.
- If no version information exists about a file,
then the file has never been opened and any version can be opened.
- The file operation finally records the version of the file.
- The directory operations are very similar.
Since this algorithm requires tracking the last version of every file that
has been accessed by an entity or user in the past, the view consistency
database can become very large. A database
truncation algorithm is required.
