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

Write a short note on built in function in qbe, Write a short note on built...

Write a short note on built in function in QBE? Built in function in QBE: QBE involves various built in functions like AVG, MAX,MIN,SUM and CNT. We must prefix these operator

Explain the use of constraints in functional model, Explain the use of cons...

Explain the use of constraints in functional model with suitable example. A constraint shows relationship between two objects at same time, or   among various values of the sam

What is a primary index, What is a primary index? A primary index is an...

What is a primary index? A primary index is an index whose search key also explains the sequential order of the file.

Decompose the table with the functional dependencies, Decompose the table w...

Decompose the table with the following description and functional dependencies into a set of equivalent tables normalized to 3NF or BCNF. This database stores records from a (ve

What is 2nf, What is 2NF? A relation schema R is in 2NF if it is in 1NF...

What is 2NF? A relation schema R is in 2NF if it is in 1NF and every non-prime attribute A in R is fully functionally dependent on primary key.

Set difference, Set Difference If R1 and R2 are two union compatible re...

Set Difference If R1 and R2 are two union compatible relations or relations then result of R3 =R1- R2 is the relation that have only those tuples that are in R1 but not in R2.

Explain the disadvantages of file oriented approach, Explain the disadvanta...

Explain the disadvantages of file oriented approach? In the oriented approach Applications are designed in isolation. Design of application is optimized for one application. In

Explain clustering file organization, Explain Clustering file organization ...

Explain Clustering file organization (i) Determine if a record of file is physically ordered on a nonkey field - that does not comprise a different value for each record - that

Components of a typical database environment, Question: (a) List four d...

Question: (a) List four disadvantages of the File Processing System as compared to the Database Systems. (b) The integrity of a database is enforced by integrity rules. One

Give the forms of triggers, Give the forms of triggers? The triggering ...

Give the forms of triggers? The triggering event can be insert or delete. For updated the trigger can state columns. The referencing old row as clause The referencing

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