Strict 2pl-two phase locking (2pl), Database Management System

Assignment Help:

Strict 2PL:Though, this basic 2PL suffers from the trouble that it can result into loss of isolation / atomic property of transaction as theoretically speaking once a lock is released on a data item it can be changed by another transaction before the first transaction aborts or commits.

To leave such a situation we use strict two phase locking. The strict 2PL is graphically depicted in Figure. Though, the basic drawbacks of strict 2PL are that it restricts concurrency as it locks the item afar the time it is required by a transaction.

                                 693_Strict 2PL.png

                                                           Figure: Strict Two Phase Locking

Does the two phase locking solve all the problems of concurrent transactions? No, the strict 2PL answers the problem of concurrency and atomicity, though it introduces another problem.


Related Discussions:- Strict 2pl-two phase locking (2pl)

Managing Data in Databases, Answer SQL Queries to extract data from data ta...

Answer SQL Queries to extract data from data tables and questions on mapping conceptual data models into relational data model.

Erd, er diagram on cosmetics.

er diagram on cosmetics.

What is object containment, What is object containment? References amon...

What is object containment? References among objects can be used to model dissimilar real-world concepts.

Storage of database on hard disks, Storage Of Database On Hard Disks At...

Storage Of Database On Hard Disks At this point, it is worthwhile to note the difference among the terms file Organisation and the access method. A file organisation shows to t

What is candidate key, What is candidate key? Candidate Key - A candi...

What is candidate key? Candidate Key - A candidate key of an entity set is a minimal superkey, which uniquely identifies each row in the relation.

Conversion of er diagram to relational database, Conversion of entity sets:...

Conversion of entity sets: I)   For  every  strong  entity  type  E  in  the  ER  diagram,  we  make  a  relation  R containing all the easy attributes of E. The relation R pri

Create a database schema, Consider a database schema consisting of four rel...

Consider a database schema consisting of four relations, whose schemas are: Product (maker, model, type) PC (model, speed, ram, hd, price) Laptop (model, speed, ram, hd, s

E - r schema with weak entity, Consider the E/R schema with weak entity set...

Consider the E/R schema with weak entity sets shown below. Come up with the SQL CREATE TABLE statements (with appropriate primary key, unique and foreign key constraints). Include

Computing the closure of a set of functional dependency, What is meant by c...

What is meant by computing the closure of a set of functional dependency? The closure of F denoted by F + is the set of functional dependencies logically implied by F.

Explain the term- signal-to-noise ratio, Explain the term- signal-to-noise ...

Explain the term- signal-to-noise ratio A signal-to-noise ratio of 20 dB means that S/N = 100. As log2101 is around 6.658, the Shannon limit is around 19.975 kbps. The Nyquist

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