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

Describe difference between a one-to-many and a many-to-many, Describe the ...

Describe the difference between a one-to-many and a many-to-many relationship. Which logical data structures comprise one-to-many and which comprise many-to-many relationship?

Project, Preliminary entities and attributes of human resourse management d...

Preliminary entities and attributes of human resourse management database management system

Create a e-r diagram, Information about films holds information about movie...

Information about films holds information about movies, stars and studios. Movies have a title, year of production, length and the film type. Stars have a name and address. Studi

One to many - relationship cardinality, One-to-many : An entity in A is rel...

One-to-many : An entity in A is related with any number of entities in B. An entity in B is related with at the most one entity in A. Example: Relationship between faculty and d

ENTITY DIAGRAMS IN FIRST NORMAL FORM, CAN SOMEONE HELP ME WITH ENTITY DIAGR...

CAN SOMEONE HELP ME WITH ENTITY DIAGRAMS IN FIRST NORMAL FORM?

The structured query language, The Structured Query Language INTRODUCT...

The Structured Query Language INTRODUCTION Database is an organised set of information about an entity having controlled redundancy and serves numerous applications. DBMS

Implement a cache simulator, You are required to program (in a high level l...

You are required to program (in a high level language such as C, C++, Java) and implement a cache simulator which will have the following inputs and outputs:- INPUTS

Partial relation emp-get the details people with min salary, Let consider t...

Let consider the given partial relation EMP. Let us make some sub-queries for them EMPNO ENAME JOB SAL DEPTNO 7566

Explain what is relation, Explain What is Relation? A database relatio...

Explain What is Relation? A database relation is a predefined row or column format for storing information in a relational database. Relations are equal to tables.

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