Solution

The Correct answer is:  Option 3 (A, B, D Only)

Key Points

Explanation of Statement A:

• A non-serial schedule is said to be conflict serializable if it is conflict-equivalent to some serial schedule.
• This statement is correct because conflict serializability ensures that the given non-serial schedule can be transformed into a serial schedule by swapping non-conflicting operations.
• Conflict serializability is a stricter condition compared to other serializability concepts.

Explanation of Statement B:

• A non-serial schedule is said to be view serializable if it is view-equivalent to some serial schedule.
• This statement is correct because view serializability is based on the equivalence of the "view" of transactions. It allows for more flexibility compared to conflict serializability.
• View serializable schedules ensure that the initial reads, writes, and final writes in transactions are equivalent to some serial schedule.

Explanation of Statement C:

• A schedule is said to be serial if instructions of participating transactions are chronologically interleaved with each other.
• This statement is incorrect because in a serial schedule, the transactions are executed one after the other, without interleaving. Interleaving is a characteristic of non-serial schedules.
• The given definition conflicts with the actual definition of a serial schedule.

Explanation of Statement D:

• A conflict-serializable schedule will be view-serializable also but vice-versa may not be true.
• This statement is correct because conflict serializability is a subset of view serializability. A conflict-serializable schedule will always satisfy view serializability conditions.
• However, the reverse is not always true because view serializability allows for certain scenarios that conflict serializability does not.