self doubt

Question

every strict recoverable schedule is conflict serializable..if not then why?

Answer 1

@samarpita

A schedule is strict - has the strictness property - if for any two transactions T1, T2, if a write operation of T1 precedes a conflicting operation of T2 (either read or write), then the commit or abort event of T1 also precedes that conflicting operation of T2…

Any strict schedule is cascade-less, but not the converse. Strictness allows efficient recovery of databases from failure...

 

@@ https://www.youtube.com/watch?v=Jw3jDTAXuAk 

 

1. https://gateoverflow.in/79467/What-is-strict-recoverable-schedule 

 

2. https://gateoverflow.in/66950/Serializablity-and-recoverability-of-schedules 

 

3. https://gateoverflow.in/297550/Madeeasy-test-series-2019-databases-transaction-concurrency

 

 

Comments

@Awe111 I am asking about serializability….any strict recoverable schedule is serializable or not?

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@samarpita

Serializability any strict recoverable schedule is serializable ...

 

Answer 2

yes this is true  every strict recoverable schedule is conflict serializable.

 

Strict schedule:

if a transaction T1 perform W(A)  then T(2) should not allowed  to R(A) or W(A)  till  T(1)

COMMIT OR ROLLBACK

 

now you know every strict schedule is conflict but every conflict sehedule is not strict

Answer 3

Every Serial Schedule is a Strict Schedule by definition. But not every Strict Schedule is a Serial Schedule.

Every Strict Schedule is Conflict Serializable (there are no conflicts in Strict Schedules to begin with) but not every Conflict Serializable Schedule is Strict.

Answer 4

No, every strict recoverable schedule is not conflict serializable. Because

T1	T2
R(x)
	R(y)
W(y)
	w(x)

It is not conflict serializable but it is strict schedule.