Define granularity and hierarchy of granularity of locks, Database Management System

Assignment Help:

Define granularity, hierarchy of granularity of locks & multiple granularity locking. Explain the modified two phase locking along with multiple granularity locking.

Ans: The size of the data item selected as a unit of protection through a concurrency control protocol is granularity. 

When the granularity is denoted in a hierarchical structure in which each node denotes data items of different sizes we acquire the hierarchy of granularity. 

In multiple granularity locking there are three kinds of locks - shared, exclusive and intention lock.

 Modified two-phase locking strategy

1)  No lock can be granted once any node has been unlocked

2)  No node might be locked till its parent has an intention lock

3)  No node might be unlocked till all its descendants are unlocked.


Related Discussions:- Define granularity and hierarchy of granularity of locks

Explain the structured decomposition, Differentiate between the object orie...

Differentiate between the object oriented decomposition and the structured decomposition? Process-oriented (structural) decomposition divides a complex process, function or tas

Mapping, external and internal mapping with examples

external and internal mapping with examples

A step-wise distributed database design methodology, A step-wise distribute...

A step-wise distributed database design methodology Following is a step-wise methodology for distributed database design. (1) Examine the nature of distribution. Find out wh

Define an abstraction, Define an abstraction by which relationships are tre...

Define an abstraction by which relationships are treated as higher level entities Ans: Aggregation.  It is an abstraction by which relationships are treated as higher level

Search the salary of employees who are not ‘analyst’ , Example- Search the ...

Example- Search the salary of employees who are not 'ANALYST' but get a salary below than or equal to any people employed as 'ANALYST'. SELECT EMPNO, ENAME, JOB, SAL FROMEMP

What is a dataset, What is a dataset? A dataset is an in-memory databas...

What is a dataset? A dataset is an in-memory database that is disconnected from any regular database, but has all the significant characteristics of a regular database. Dataset

State about the use case diagram, State about the Use Case Diagram A u...

State about the Use Case Diagram A use case diagram represents a set of use cases, actors and their relationships. These diagrams shall be used to model context or requirement

Define network dbms, Define Network DBMS The NDBMS is built primarily o...

Define Network DBMS The NDBMS is built primarily on a one-to-many relationship, but where a parent-child representation between the data items cannot be ensured. This may occur

What is the meaning of recovery, What is the meaning of Recovery? In d...

What is the meaning of Recovery? In deferred update methods, if a transaction fails before arriving its commit point, it will not have altered the database in any way, so UNDO

What is the need of a log in a dbms, What is the need of a log in a DBMS? B...

What is the need of a log in a DBMS? Briefly describe the various types of records that are normally present in a log.            Ans:  The system log, which is generally writt

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