Consider aserial schedule which involves 3 data items A,

Consider aserial schedule <T ₀ ,T ₁ ,T ₂ > which involves 3 data items A, B, C with initial value 1000, 2000, 800, respectively. Assuming the sytem has crashed, for any of the following log files, state the corresponding recovery plan (i.e list the transactions needed to be undone and redone in order and for each transacton T, state the values of the data items that are involved in the transaction T after the undone and redone operation)

a. <T ₀ ,start>, <T ₀ , A, 1000, 900>, <T ₀ , B, 2000, 2100>

b. <T ₀ , start>, < T ₀ , A, 100, 900>, <T ₀ , B, 2000, 2100>, <T _0, commit>, < T ₁ , start>, <T ₁ , C, 800, 900>

c. <T ₀ , start>, <T ₀ , A, 1000, 900>, < T _0, B, 2000, 2100>, <T ₀ , commit>, <T ₁ , start>, <T ₁ , C, 800, 900>, <T _1, commit>, <T ₂ , C, 900, 1000>

d. <T ₀ , start>, <T ₀ , A, 900>, <T ₀ , B, 2100>

e. <T ₀ , start>, < T ₀ , A, 900>, <T ₀ , B, 2100>, <T ₀ , commit>, <T ₁ , start>, <T ₁ , C, 900>, <T ₁ , commit>, <T ₂ , C, 900,1000>