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Multiversion Concurrency Control
The basic idea
Example
Implementation using S2PL:
T2
: R(A), R(B), W(A), W(B).
T1
: R(A), R(B).
T1
T2
X(A)
R(A)
W(A)
S(A)
X(B)
R(B)
W(B)
U(B)
U(A)
commit
R(A)
S(B)
R(B)
U(B)
U(A)
commit
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