Briefly describe concurrency execution, Database Management System

Assignment Help:

Briefly describe concurrency execution?

Lock - based protocols

Locks

There are several modes in which a data item may be locked in this section we restrict our attention to two modes

Ø   Shared

Ø   Exclusive

T1 : lock - x(B );

read(B);

B:=B-50;

write(B);

unlock(B);

Lock-x(A);

read(A);

A:=A+50;

write(A);

unlock(A).

 

 


Related Discussions:- Briefly describe concurrency execution

Why like predicate used for, Why Like predicate used for? LIKE predicat...

Why Like predicate used for? LIKE predicate: The LIKE predicate searches for strings in which have a certain pattern.

What are the technique to define a schema completely, What are the techniqu...

What are the technique to define a schema completely ? A schema is completely define by DDL and DML query language.

Can you scan double-sided documents and remove blank pages, Can you scan do...

Can you scan double-sided documents - and remove blank pages? Our software and imaging systems supports duplex scanning, at the same time scanning both sides of a page. Program

What is called a query evaluation plan, What is called a query evaluation p...

What is called a query evaluation plan? A sequence of primitive operations that can be used to assess a query is a query evaluation plan or a query implementation plan.

What is deadlock, What is deadlock? How can it be avoided? How can it be re...

What is deadlock? How can it be avoided? How can it be resolved once it occurs? Deadlock happens when two transactions are each waiting on a resource that the other transaction

What are partial and natural key, What are partial, alternate,, artificial,...

What are partial, alternate,, artificial, compound and natural key? Partial Key: It is a set of attributes that can uniquely recognize weak entities and that are related to s

Relation schema for student, Example RELATION SCHEMA for STUDENT: STU...

Example RELATION SCHEMA for STUDENT: STUDENT (Roll No: string, name: string, login: string, age: integer) RELATION INSTANCE

Write a query that uses the union operator, Write a Query that uses the UNI...

Write a Query that uses the UNION Operator 1. Use the Software Experts database to:   a. Display the first and the last name of all consultants who worked on any projects f

Mobile database, write short note on mobile database

write short note on mobile database

What does conceptual design work, What does conceptual design work? A c...

What does conceptual design work? A conceptual design involves modelling independent of the DBMS.

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