Please show step by step: Transactions: T1: R(x), R(y), W(x), W(y), C T2: R(x),

ID: 3532225 • Letter: P

Question

Please show step by step:
Transactions:

History:

H1: R2(x), W2(x), R1(x), R1(y), R3(z), R3(y), W1(x), W1(y), C1, W3(y), C3, R2(z), W2(z), C2
H2: R2(x), W2(x), R3(z), R3(y), R2(z), W2(z), R1(x), W3(y), R1(y), C2, C3, W1(x), W1(y), C1
H3: R2(x), W2(x), R3(z), R3(y), R2(z), W2(z), C2, R1(x), R1(y), W1(x), W1(y), C1, W3(y), C3
H4: R3(z), R2(x), W2(x), R1(x), R3(y), W3(y), C3, R1(y), W1(x), W1(y), C1, R2(z), W2(z), C2
H5: R1(x), R1(y), R3(z), W1(x), W1(y), C1, R2(x), R3(y), W2(x), W3(y), C3, R2(z), W2(z), C2

Here are 5 histories, for each one of them:

Find out if the history is recoverable, if it is recoverable, find out if it avoids cascading abort.
Find out if the history is conflict serializable, if it is conflict serializable, SHOW which serial history it is equivalent to

Please show step by step:
Transactions: History: Here are 5 histories, for each one of them:

Find out if the history is recoverable, if it is recoverable, find out if it avoids cascading abort.
Find out if the history is conflict serializable, if it is conflict serializable, SHOW which serial history it is equivalent to

1. Serizability (or view) cannot be decided but NOT conflict serizability. It is recoverable and avoid

cascading aborts; NOT strict

2. It is serializable, conflict-serializable, and view-serializable regardless which action (commit or abort)

follows It is NOT avoid cascading aborts, NOT strict; We can not decide whether it's recoverable or

not, since the abort/commit sequence of these two transactions are not specified.

3. It is the same with 2.

4. Serizability (or view) cannot be decided but NOT conflict serizability. It is NOT avoid cascading

aborts, NOT strict; We can not decide whether it's recoverable or not, since the abort/commit

sequence of these transactions are not specified.

5. It is serializable, conflict-serializable, and view-serializable; It is recoverable and avoid cascading

aborts; it is NOT strict.

6. It is NOT serializable, NOT view-serializable, NOT conflict-serializable; it is recoverable and avoid

cascading aborts; It is NOT strict.

7. It belongs to all classes

8. It is serializable, NOT view-serializable, NOT conflict-serializable; It is NOT recoverable, therefore

NOT avoid cascading aborts, NOT strict.

9. It is serializable, view-serializable, and conflict-serializable; It is NOT recoverable, therefore NOT

avoid cascading aborts, NOT strict.

10. It belongs to all above classes.

11. It is NOT serializable and NOT view-serializable, NOT conflict-serializable; it is recoverable, avoid

cascading aborts and strict.

12. It is NOT serializable and NOT view-serializable, NOT conflict-serializable; it is recoverable, but NOT

avoid cascading aborts, NOT strict.