DB: How to draw a precedence graph (rules + 3 examples)
Channel: LernenInVerschiedenenFormen
Date: 2018-01-22

From the conversation with Adi Nagara@3rd example:
You have indeed no global cycle of all transactions. But you have a cycle in T1,T2.  You could indeed say, that {T1, T2} (as one entity) and {T3} is conflict serializable. 
Though, in this example I don't look at it in that way. My statement of "conflict serializable" / "not conflict serializable" refers to all transaction. So I mean "all transaction are conflict serializable" or "all transactions are not conflict serializable". 
If you're concerned about exams, you should ask your teacher in which way he wants the statement to be. 


Comment from TNH91 (didn't verify this content yet): 
"If two different transactions contain at least one write and one (read/write) on the same field, then draw an arrow from the earlier to the later."


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