Explain the timestamp ordering protocol, Database Management System

Assignment Help:

Timestamp Ordering Protocol

A timestamp is a tag that can be attached to any transaction or any data item, which indicates a specific time on which the transaction or data item had been activated in any way. We, who use computers, must all be familiar with the methods of "Date Created" or "Last Modified" properties of files and folders. Well, timestamps are things like that.

A timestamp can be executed in two ways. The simplest one is to directly assign the current value of the clock to the transaction or the data item. The other policy is to attach the value of a logical counter that keeps incrementing as new timestamps are needed.

The timestamp of a transaction shows the time when it was first activated. The timestamp of a data item can be of the following two types:

W-timestamp (Q): This means the latest time when the data item Q has been written into.

R-timestamp (Q): This means the latest time when the data item Q has been read from.

 


Related Discussions:- Explain the timestamp ordering protocol

Draw an e-r diagram and convert it to a relational schema, In an organizati...

In an organization several projects are undertaken. Each project can employ one or more employees. Each employee can work on one or more projects. Each project is undertaken on the

Explain the advantages of dbms over file oriented system, Explain the main ...

Explain the main advantages of DBMS over File Oriented System ?

Multivalued attributes, For every multivalued attribute 'A', we make a new ...

For every multivalued attribute 'A', we make a new relation R that contains an attribute corresponding to plus the primary key attribute k of the relation that shows the entity typ

What are referential integrity constraints, What are referential integrity ...

What are referential integrity constraints? A value that appears in single relation for a given set of attributes also appears for a particular set of attributes in another rel

What are called index-sequential files, What are called index-sequential fi...

What are called index-sequential files? The files that are ordered sequentially with a primary index on the search key are known as index-sequential files

Objectives-distributed and client server databases, Objectives diff...

Objectives differentiate DDBMS and conventional DBMS; Describe Network topology for DDBMS; Describe the concepts of horizontal and vertical fragmentation; Descr

What is the use of a slotted-page structure, What is the use of a slotted-p...

What is the use of a slotted-page structure and what is the information are there in the header? The slotted-page structure is used for organizing records within a one block.

What is meant by functional dependencies, What is meant by functional depen...

What is meant by functional dependencies? Consider a relation schema R and α C R and β C R. The functional dependency α ->β  holds on relational schema R if in any legal relati

Define- relational algebra, Define- relational algebra. The relational ...

Define- relational algebra. The relational algebra is a procedural query language. It having of a set of operations that take one or two relation as input and make a new relati

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