In the previous article we studies about transaction concurrency. In this section we’ll learn about SCHEDULE SERIALIZIBILITY AND ITS TYPE also. We can describe SCHEDULE SERIALIZIBILITY AND ITS TYPE as a series of operation. Operation from one transaction to another. It is use to preserve the order of the operation. In each of the individual transaction.
In the meantime ,We can describe schedule’s types as follows:
SCHEDULE AND ITS TYPES:
- 1.SERIAL SCHEDULE.
- 2. NON-SERIAL OR PARALLEL SCHEDULE.
- a)SERIALIZABLE .
- a.1-Conflict schedule.
- a.2-View schedule.
- B)NON -SERIALIZABLE.
- b.1Recoverable schedule.
- b.1.1-Cascading schedule.
- b.1.2-Cascadeless schedule.
- b.1.3-Strict schedule.
- B.2Non-recoverable schedule.
In summary let’s clear it more. There are two types of schedule. Serial and Non-serial. Non serial is also known as parallel schedule. furthermore, these are divide into two. Serializable and Non serializable. Furthermore, serializable schedule are divide into two. Conflict and view schedule. lastly, Non serializable schedule are divide into recoverable and non recoverable. And lastly, recoverable are divide into cascading, Cascade less and strict schedule.
The serial schedule is type of schedule . Where one transaction is execute. Completely. Before starting another transaction. When first transaction complete its cycle. Then the next one is executed.
NON SERIAL OR PARALLEL SCHEDULE:
In the meantime, If interleaving of operations are allow ,then the schedule is non serial. It contains many possible orders. In which the system can execute the individual operation of the transactions .
READ-WRITE CONFLICT ON UREPEATABLE READ:
In addition to transaction. There are various conflicts. Furthermore, there are three types of conflict. In database transaction.
- Write Read conflict
- read write conflict
- write write conflict
Lastly ,lets discuss about SERIALIZIBILITY
In the meantime some non-serial schedule may lead to inconsistency . Serializability is a concept that helps to identify which non serializable schedule are correct. And will maintain the consistency.
In summary they behaves exactly as serial schedule. Thus these are always: consistent, cascade less, recoverable strict.
we’ll study further in the next article.