Explain the concept of two-phase locking, Database Management System

Assignment Help:

Explain the Concept of Two-phase Locking

It concerns the positions of locking and unlocking operations in each transaction.  In this protocol every transaction issue lock and unlock requests in two phases. 

Growing Phase:  In this phase a transaction might acquire locks but may not release any lock. Here the of locks rises from zero to the maximum for the transaction. 

Shrinking Phase:  In this phase a transaction might release locks but may not obtain any new locks. Here the number of locks reduces from maximum to zero. 

The major concept of this protocol is that, all the locks are first obtained before any of the locks released. No new locks can be granted later than the releasing of any lock.


Related Discussions:- Explain the concept of two-phase locking

boyce codd normal form relations, Create centralized relational database u...

Create centralized relational database using bottom up method.   (a) Recognize a single un-normalized relation for the above scenario.          (b) Recognize the primary key for

Implementation of database, The ER diagram clearly showing the additional t...

The ER diagram clearly showing the additional tables you have implemented. SQL table creation scripts for the tables you have set up. SQL scripts showing the sample data you

RDBMS, what is RDBMS? how it works? good example.

what is RDBMS? how it works? good example.

Explain instance and schemas, Explain Instance and schemas? Instances ...

Explain Instance and schemas? Instances and schemas: Databases changes over time as the information is deleted and inserted. The collection of information stored in database

Which component is not included in database environment, Which component is...

Which component is not included in database environment ? A users component is not included in database environment.

A file manipulation command that extracts some records, A file manipulation...

A file manipulation command that extracts some of the records from a file is called ? A file manipulation command that extracts some of the records from a file is called SELECT

ER diagram in database, What is an ER diagram? Why is it used in Database m...

What is an ER diagram? Why is it used in Database management system (DBMS)?

Analyzing association traversal, Analyzing Association Traversal Assoc...

Analyzing Association Traversal Association Traversal shall be understood properly for the association design explanation.  Analyzing association traversal means analyzing tra

Adjustments are required to increase chances of inheritance, What types of ...

What types of adjustments are required to increase chances of inheritance. a)   Some attributes can be added or ignored in  the base class operation  b) Some changes can be

Domains, Every simple attribute of an entity type have a possible set of va...

Every simple attribute of an entity type have a possible set of values that can be attached to it. This is known as the domain of an attribute. An attribute cannot have a value out

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