Explain The Difference Between An Exclusive Lock And A Shared Lock.
Exclusive locks protect updates to the file resources both recoverable and nonrecoverable.they can be owned by one transaction at a time. any transaction that requires an exclusive lock must wait if another task currently owns an exclusive lock ar a shared lock against the requested resource.
shared lock reserves its object(transaction) for read only.they ensure that a record isn't in the process of being updated during a read-only request.it can be used to prevent updates of a record between the time that a record is read and the next synchronous point. it prevents the object from changing while lock remains. mor than one program can place a shared lock on the same object.
note: shared lock allows other users to read the locked resources, but they cant update it.
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