• 2PL(Two Phase :Locking) :--
    • Two Phase Locking Is a mathode or
    • Two-phase locking is a method or protocol, to control concurrent access, which works in two phases:protocol ,to control concurrent acces.
    • which work in two phase
      • Growing  Phase
      • Shrinking Phase
  • Growing Phase :-
    • A transaction may obtain locks, but, cannot release any lock
    • A time, when a transaction obtains its final lock, is called Lock point for that transaction.
  • Shrinking Phase :-
    • A transaction may release locks, but, cannot obtain any new lock.
    • This technique ensures serializability. And it is used to maintain level-3 consistency.
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