Transaction states, Database Management System

Assignment Help:

The following variant of the primary copy asynchronous-update replication protocol has been proposed for totally replicated systems.

(a)  A transaction executing at site A updates only the replicas at A before it commits (it needed to access no other site since replication is total).

(b)  After the transaction commits, a second transaction is initiated to update the primary copies of all items updated at A.

(c)  After the transaction in step (b) has completed, each primary site propagates the update made at that site to all secondaries (including the one at site A). Updates made to a primary copy by several transactions are propagated to secondaries in the order in which the primary was updated.

Explain why, in step (b), all primaries must be updated in a single transaction and, in step (c), the update is propagated to site A.

 


Related Discussions:- Transaction states

Cube building in dataware housing , 1) Define a job scheduling strategy tha...

1) Define a job scheduling strategy that will meet business requirement of reporting availability by 6am CST for the following cubes? Show the job scheduling dependencies in a pict

Entity - relation modeling and transformation, Represent the following scen...

Represent the following scenarios with E-R diagrams drawn using the ER Assistant software. The diagrams should indicate cardinality and optionality of relationships. Transform each

Datawarehouse Case studies, I have been given 8 differebt data warehouseing...

I have been given 8 differebt data warehouseing failure case studies. I need to question 4 questions for each

Differance between join and outer join, Differentiate between join and oute...

Differentiate between join and outer join? Outer joins return all rows from at least one of the tables or views mentioned within the FROM clause, as long as those rows get toge

Transaction managenment, can you please explain with the help of suitable e...

can you please explain with the help of suitable example the difference between conflict equivalence and conflict serializability?

Define object-relational systems, Define object-relational systems? Sy...

Define object-relational systems? Systems that give object-oriented extensions to relational systems are known as object-relational systems.

What is serializability, What is serializability? Explain its types? Th...

What is serializability? Explain its types? The data base system must control concurrent implementation of transactions, to ensure that the data base state remains consistent.

Naïve bayesian approach-id3 algorithm, You are working for the ABC Telecom ...

You are working for the ABC Telecom and are given some customer records for data mining. You are asked to discover, from the data, patterns that characterize low-, medium- and high

Anomalies, define anomalies and different types of anomalies with example

define anomalies and different types of anomalies with example

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