What is system log, Database Management System

Assignment Help:

What is system log?  What are the entries?      

Ans:  The system log that is generally written on stable storage contains the redundant data required to recover from volatile storage failures and as well from errors discovered by the transaction or the database system. System log is as well known as log and has sometimes been called the DBMS journal. It consists of the following entries (also known as log records):

a. [start_transaction, T]: Points out that transaction T has started execution.

b. [write_item, T, X, old_value, new_value]: Points out that transaction T has changed the value of database item X from old_value to new_value.

c. [read_item, T, X]: Points out that transaction T has read the value of database item X.

d. [commit, T]: Points out that transaction T has completed successfully, and affirms that its effect can be committed (recorded permanently) to the database.

e. [abort, T]: Points out that transaction T has been aborted.


Related Discussions:- What is system log

What is online transaction processing, What is OLTP (Online Transaction Pro...

What is OLTP (Online Transaction Processing)? In OLTP - online transaction processing systems relational database design use the discipline of data modeling and generally follo

Datawarehouse, Define a job scheduling strategy that will meet business req...

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 pictori

What is olap, What is OLAP? OnLine Analytical Processing (OLAP) is a Bu...

What is OLAP? OnLine Analytical Processing (OLAP) is a Business Intelligence (BI) reporting system. OLAP gives the user with the capability to sum, count, average and do other

Explain the concept of modeling with objects, Explain the concept of Modeli...

Explain the concept of Modeling With Objects A model is a conceptual representation of a specification, design or system from a particular point of view. A modelling language

Database Management System, Assume that you are responsible for selecting a...

Assume that you are responsible for selecting a new DBMS product for Sohar Hospital

What is an index as defined in oracle, Normal 0 false false ...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Normalization-e-r mapping , Normalize the following table upto and includin...

Normalize the following table upto and including the 3NF. Submit a 1 page printout of only the final set of normalized tables in Data Architect. Just use Data Architect to do the t

Property management database, You are to write a property management databa...

You are to write a property management database program that allows a real estate agent to view, add, search, and save property listings. The program is to do the following: 1.

Explain the terms data warehousing and data mining, Question: i) Explai...

Question: i) Explain the terms data warehousing and data mining. ii) Discuss the importance of the following security principles that a digital firm should amongst others, n

What is inheritance, What is inheritance? Define it in detail?  Inheri...

What is inheritance? Define it in detail?  Inheritance Inheritance can be at the levels of types, or at the level of tables we first consider inheritance of types, then i

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