Describe log based recovery, Database Management System

Assignment Help:

Describe log based recovery

The most usably structure for recording data base modification is the LOG the log is a sequence of log records recording all the update activities in the data base. There are several types of log records. An update log records describes a single data base write it has these fields

Transaction identifier

Data item identifier

Old value

New value

The various types log records as.

  • < Ti start >. Transaction Ti has started
  • < Ti , Tx v1,v2 > .Transaction Ti has performed a right on data item
  • < Ti commit > Transaction Ti has committed
  • < Ti about > Transaction Ti has aborted

Ø  Deferred data base modification

Ø  Immediate data base modification

Ø  Check point

Ø  Shadow paging

 


Related Discussions:- Describe log based recovery

With the help of a diagram defines typical element modules, With the help o...

With the help of a diagram defines the typical element modules of a DBMS? The functional elements of a database system can be widely divided into: 1) Storage manager and 2) q

Define database management system, Define database management system? D...

Define database management system? Database management system (DBMS) is a set of interrelated data and a combination of programs to access those data.

Explain displaying an er schema as an er diagram, Explain the conventions f...

Explain the conventions for displaying an ER schema as an ER diagram? An E-R Diagram scheme might describe certain constraints to that the contents of a database must conform.

Query optimization, what is meant semantic query optimization? how does it ...

what is meant semantic query optimization? how does it differ from other query optimization techniques?

Special workarea for interface, While using extract datasets it is required...

While using extract datasets it is required to have a special workarea for interface False.  It is not required to have a special workarea for interface

Describe the definition of a transaction in sql, Describe the definition of...

Describe the definition of a transaction in SQL  Ans: The SQL transaction starts implicitly. Transactions are finished by either Commit work that commits the transaction and st

Which is another name for weak entity, Which is another name for weak entit...

Which is another name for weak entity? Child is another name of weak entity.

Explain query tree represent relational algebra expression, How does a quer...

How does a query tree represent a relational algebra expression?      Ans: This includes transforming an initial expression (tree) into an equivalent expression (tree) that is

What are the two methods for dealing deadlock problem, What are the two met...

What are the two methods for dealing deadlock problem? The two procedures for dealing deadlock problem is deadlock detection and deadlock recovery.

Write short note on events, Write short note on Events Events consist ...

Write short note on Events Events consist of inputs, interrupts, decisions and actions performed by any external device or users. Every event always has a sender and receiver.

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