When are two schedules said to be view equivalent, Database Management System

Assignment Help:

When are two schedules said to be view equivalent?    

Ans: Two schedules that is denoted as S and S' are said to be view equivalent if the subsequent three conditions are met

1)  For every data item Q, if a transaction Ti reads the initial value of Q in schedule S, after that transaction Ti should in schedule S'  also read the initial value of Q.

2)  For every data item Q, if a transaction Ti executes read(Q)  in schedule S and that value was generated by Tj (if any) , then transaction Ti must in schedule S'  as well read the value of Q generated by Tj.

3)  For every data item Q, if a transaction if any that carries out the final write(Q) in schedule S should perform the final write(Q) in schedule S'.


Related Discussions:- When are two schedules said to be view equivalent

North indian plains, i am not clear with the climetic condition of the nort...

i am not clear with the climetic condition of the north indian plain. can u plz explain it for me

ER diagrams, explain exhaustively the problems associated with ER diagrams....

explain exhaustively the problems associated with ER diagrams. include illustrations in your answer

What is d command work in the respect of qbe, What is D command work in the...

What is D command work in the respect of QBE? D: It is the command inside QBE to delete tuple(s) from the relation.

Describe application programming interface, Describe Application programmin...

Describe Application programming interface? Application Programming Interface - Commercial SQL implementations take one of the two primary techniques for involving SQL in a p

What are composite attributes, What are composite attributes? Composite...

What are composite attributes? Composite attributes can be separated in to sub parts.

Relational schema, crete a data base relationship model Entity: ...

crete a data base relationship model Entity: Students; Professors; Dormitories buildings; Attributes of students: Name; Address; Dorm;

Compare wait-die deadlock prevention with wait-wound scheme, Compare wait-d...

Compare wait-die deadlock prevention scheme with wait-wound scheme   Ans:  Wait-Die Scheme  a) Based upon a nonpreemptive technique.  b) If Pi requests a resource present

Differentiate between b-tree and b+ tree, Differentiate between B-tree and ...

Differentiate between B-tree and B + tree    Ans:  A B-tree (or Balanced Tree) is a search tree along with additional constraints that makes sure that the tree is all the time

Clinic, Need a sample of a clinic database relationships

Need a sample of a clinic database relationships

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd