A transaction that follows the 2PL protocol can be divided in to 2 phases.
* Expanding phase-new lock on items can acquire but NONE can be released
* shrinking phase-existing locks can be released but no new locks can acquire
2 Phase Lock may limit the amount of concurrency that can occur in a schedule.
Two Phase locking protocol prevent deadlock. This protocol maintain the schedule which lock should be granted or not. For more information I think this link help you. http://www.databaseidea.com/2012/03/two-phase-locking-protocol.html
File Transfer Protocol.
ADVANTAGE: It produces only cascadeless schedules, recovery is very easy.DISADVANTAGE: The set of schedules obtainable is a subset of those obtainable from plaintwo phase locking, thus concurrency is reduced
Central locking on madza 2 not working
In two phase locking there are two phases. The first phase is known as Expanding Phase and locks are issued in this phase. No lock is released. Then after change all changes are committed and the second phase starts that is the Shrinking Phase in which all the changes are noted and the locks are released. No locks are issued in this phase
protocol is a connection establishment between the source computer to destination computer ex: tcp / ip protocol
Two-phase locking (2PL) is a concurrency control protocol used in database management systems to ensure that transactions are executed in a serializable manner. It operates in two phases: the growing phase, where a transaction can acquire locks but cannot release them, and the shrinking phase, where it can release locks but cannot acquire new ones. This locking mechanism prevents conflicts between transactions and ensures that the final result is the same as if the transactions were executed serially. By adhering to this protocol, 2PL guarantees that the interleaving of transactions does not lead to anomalies, thus preserving the integrity of the database.
the various types of locking in vb are as follows:- 1. RdConcurReadOnly 0 (Default) 2. RdConcurLock 1 (Pessimistic Locking) 3. RdConcurRowver 2 (Optimistic Locking) 4. RdConcurValues 3 5. RdConcurBatch 4
PhASE 2
Game phases? If you mean the phases for a turn in Yu-Gi-Oh then here they are: Draw Phase Standby Phase Main Phase 1 Battle Phase Main Phase 2 End Phase
In standard installations in many countries a 240v outlet does not have to be a locking type. However in many businesses and even homes in some counties the plug does have to lock. Check the local building codes to be sure.
The strict two-phase locking (S2PL) class of schedules is the intersection of the 2PL class with the class of schedules possessing the Strictness property. To comply with the S2PL protocol a transaction needs to comply with 2PL, and release its write (exclusive) locks only after it has ended, i.e., being either committed or aborted. On the other hand, read (shared) locks are released regularly during phase 2. Implementing general S2PL requires explicit support of phase-1 end, separate from transaction end, and no such widely utilized product implementation is known. S2PL is a special case of 2PL, i.e., the S2PL class is a proper subclass of 2PL