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

Determine the advantage of object-orientation, Determine the advantage of o...

Determine the advantage of object-orientation Finally, object-orientation has advantage of continuity throughout analysis, persistent representation and design implementation.

What is odbc and what is its function, Question: (a) What is ODBC and w...

Question: (a) What is ODBC and what is its function? (b) What is Web application server, and how does it work from a database perspective? (c) What does e-commerce mean

What is equi join, What is equi join? Equi Join - It generates all th...

What is equi join? Equi Join - It generates all the combinations of tuples from two relations which satisfy a join condition along with only equality comparison (=).

What is a database graph, What is a database graph? The partial orderin...

What is a database graph? The partial ordering implies that the set D may now be viewed as a directed acyclic graph, known as a database graph.

Entity integrity, Before defines the second type of integrity constraint, v...

Before defines the second type of integrity constraint, viz., Entity Integrity, we should be well-known with the concept of NULL. Mostly, NULL is intended as a basis for dealing

Increased overheads on update-data replication, Increased overheads on upda...

Increased overheads on update : On the drawbacks side, it will need the system to ensure that all replicas of a relation are consistent. This shows that all the replicas of the rel

ER diegrams, How to draw an ER diagram to a finance companz

How to draw an ER diagram to a finance companz

Describe the iterative and incremental life cycle, Describe the iterative a...

Describe the iterative and incremental life cycle For an iterative and incremental life cycle, two criteria are process and time. The main components of showing a project devel

Describe the two alternatives for specifying structural, Describe the two a...

Describe the two alternatives for specifying structural constraints on relationship kinds? Relationship kinds have certain constraints in which limit the possible combination o

Define query optimization, Define query optimization. Query optimizatio...

Define query optimization. Query optimization refers to the process of search the lowest -cost method of evaluating a given query.

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