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

State the step- implement software control designer, Implementing software ...

Implementing software control To implement software control designer must redesign strategy of state event model which is present in dynamic model. There are three basic ap

Explain the role of a database administrator, Explain the Role of a databas...

Explain the Role of a database administrator a. Defining the Schema   The DBA describes the schema which consists of the structure of the data in the application. The DBA

Explain the need for the bcnf normal form, Surgeons identified by doctor ID...

Surgeons identified by doctor ID (DOCID) operate on patients identified by patient ID (PATID) in operating theaters identified by room numbers (ROOMNO). Each surgeon can operate on

What are data models, What are data models? Explain it detail? Entity ...

What are data models? Explain it detail? Entity relationship model Rectangles Ellipse Diamonds Lines Relational model Relational model use a collection

What is icr, What is ICR? A. ICR (Intelligent Character Recognition) is...

What is ICR? A. ICR (Intelligent Character Recognition) is a technology that gives scanning and imaging systems the ability to identify images of hand-printed or script charact

Answer, what is database management system? & why it is required?

what is database management system? & why it is required?

How can you terminate the mysql server, How can you terminate the MySQL Ser...

How can you terminate the MySQL Server? Typing the following in Command prompt will shut down the server completely as root user % mysqladmin -u root -p shutdown

Entity relationship diagram, The Enhanced Entity Relationship Diagram (ERD)...

The Enhanced Entity Relationship Diagram (ERD) produced with a drawing or case tool. Your EERD must use a ''standard'' notation style such as Crows Foot or Chen. Please note that t

What is rigorous two phase locking protocol, Differentiate strict two phase...

Differentiate strict two phase locking protocol and rigorous two phase locking protocol. In strict two phase locking protocol all exclusive mode locks taken by a transaction is

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