Serializability

1. Conflict Serializable :-- If a given schedule can be converted to another one without swapping two conflicting instructions then its conflict serializable. (A bit more strict)

Testing whether a particular schedule is conflict serializabile is a simple polynomial time complex problem. 

2. View Serializable :-- A superset of above, where for external person two schedule produce same output and no inconsistency. ( A bit more lenient)

Testing whether a particular schedule is view serializable is an NP complete problem.