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- Simplicity - the algorithm should be simple and flexible
- Operation Logging - to provide support for semantically rich lock modes
The disadvantage of value logging is the amount of space used. This can
be reduced using operation logging (logical logging).
- Flexible Storage Management - it should provide support for logical
locking and logging so that movements of data within a page for garbage
collection reasons do not cause the moved data to be locked or the
movements to be logged
- Partial Rollbacks - it should support partial rollbacks which are
necessary to avoid total rollbacks in situations like integrity
constraint violations, obsolete data in cache, ...
- Flexible Buffer Management - the recovery method should make least no. of
assumptions about the Buffer Management policy, but should also take
advantage of the specific policy lying underneath
- Recovery Independence -
- it should be possible to image copy (archive dump) and perform restart
recovery at different granularities
- recovery of one object should not force the concurrent or lock-step
recovery of another object
- it should be possible to do selective recovery and defer recovery of
some objects to a later point in time to speed up restart and also to
accommodate some offline devices
- Logical Undo
- undo the effect of a failed transaction, without restricting the undo
operation to pages modified during forward processing
- Parallelism and fast recovery
- the recovery method has to be able to exploit the parallelism of the
underlying hardware during different stages of media recovery and
restart recovery
- the recovery method should be very fast
- it should also be possible to let the backup system start processing
new transactions even before the undo processing for the interrupted
transactions completes
- Minimal overhead - the overhead in terms of the log data volume, storage
consumption, etc. imposed by the recovery method in virtual and non
volatile storages to accomplish the above goals should be minimal.
Next: Overview of ARIES
Up: No Title
Previous: Introduction
Vinay V
Mon Apr 12 18:36:08 IST 1999