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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

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Advantages of two phase locking protocol?

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


Difference between 2-phase commit and 3-phase commit?

In a 2-phase commit protocol, there are two phases: prepare and commit. The coordinator asks all participants to prepare to commit, then all participants either agree or abort. In a 3-phase commit protocol, there are three phases: can-commit, pre-commit, and do-commit. This adds an extra phase to ensure better fault tolerance and improve the likelihood of reaching a decision.


What is 2pc protocol?

The 2-phase commit (2PC) protocol is a distributed algorithm to ensure the consistent termination of a transaction in a distributed environment. Thus, via 2PC an unanimous decision is reached and enforced among multiple participating servers whether to commit or abort a given transaction, thereby guaranteeing atomicity. The protocol proceeds in two phases, namely the prepare (or voting) and the commit (or decision) phase, which explains the protocol's name.


Explain the strict two-phase locking protocal in dbms?

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


What is the difference between two phase commit and three phase commit in distributed system?

In computer networking and databases, the three-phase commit protocol (3PC)[1] is a distributed algorithm which lets all nodes in adistributed system agree to commit a transaction. Unlike the two-phase commit protocol (2PC) however, 3PC is non-blocking. Specifically, 3PC places an upper bound on the amount of time required before a transaction either commits or aborts. This property ensures that if a given transaction is attempting to commit via 3PC and holds some resource locks, it will release the locks after the timeout.3PC was originally described by Dale Skeen and Michael Stonebraker in their paper, "A Formal Model of Crash Recovery in a Distributed System"[1]. In that work, they modeled 2PC as a system of non-deterministic finite state automata and proved that it is not resilient to a random single site failure. The basic observation is that in 2PC, while one site is in the "prepared to commit" state, the other may be in either the "commit" or the "abort" state. From this analysis, they developed 3PC to avoid such states and it is thus resilient to such failures.


What are highlights of DBMS?

NA_ what are highlights of advanced DBMS what are highlights of advanced DBMS what are highlights of advanced DBMS


Name two of dominate DBMS vendors and their latest products please specify in which way they are the dominating DBMS vendor?

oracle, Microsoft, SyBase and oracle.


What are the advantages of two phase locking?

--guarantees serializability --The protocol utilizes locks that block other transactions from accessing the same data during a transaction's life. by Raja Done M.Tech


Is java DBMS?

no, Java is not dbms.. Java is a programming language Dbms is database


Is SQL DBMS or RDBMS?

dbms


What are three types of dbms?

Hierarchical DBMSNetwork DBMSRelational DBMS


Two phase instruments?

There is no such thing as a two phase instrument. There is only single phase and three phase. You can only have: single phase/ one pole single phase/ two pole three phase/ three pole