The locking protocol, Database Management System

Assignment Help:

The Locking Protocol: To manage concurrency related problems we use locking. A lock is mainly a variable that is associated with a data item in the database. A lock can be located by a transaction on a shared resource that it needs to use. When this is completed, the data item is available for the exclusive use for that transaction that is other transactions are locked out of that data item. When the transaction that has locked a data item does not need to use it any longer, it should unlock the data item so that other transactions can use it. If a transaction attempts to lock a data item already locked by some other transaction, it cannot do so and remains for the data item to be unlocked. The parts of DBMS that controls and stores lock information is known as the Lock Manager. The locking mechanism helps us to change a schedule into a serialisable schedule. We had definite what a schedule is, but what serialisable schedule is?

 


Related Discussions:- The locking protocol

find a non-redundant cover and canonical cove, Given the following set of ...

Given the following set of functional dependencies {cf→ bg, g → d, cdg → f, b → de, d → c} defined on R(b,c,d,e,f,g) a. Is cf→ e implied by the FDs? b. Is dg a superkey?

Explain the concept of qbe, Explain the concept of QBE? Query-by-exampl...

Explain the concept of QBE? Query-by-example represents a visual/graphical approach for accessing information in a database by the use of query templates called as skeleton tab

ERD, #question.ERD of any car

#question.ERD of any car

Commercial database architecture, At its most essential level the DBMS arch...

At its most essential level the DBMS architecture can be divide into two parts: the back end and the front end. The back end is responsible for managing the physical database an

Explain cnt in the respects of qbe, Explain CNT in the respects of QBE ? ...

Explain CNT in the respects of QBE ? CNT: It is one of the aggregation commands given in QBE. It is used to identify number of tuples

Managing databases, 10A.53 Code an Oracle Database trigger to enforce the...

10A.53 Code an Oracle Database trigger to enforce the constraint that an employee can never change his or her department. 10A.54 Code an Oracle Database trigger to allow the

Express the properties of strings, Express the properties of Strings? ...

Express the properties of Strings? Strings can be case sensitive (or not) which can change the outcome of string operations. You can evaluate whole strings \ just part

Issues relating to the design of the physical database files, The issues re...

The issues relating to the Design of the Physical Database Files Physical File is a file as stored on the disk. The major issues relating to physical files are:  •      Cons

Examine about the behavioural diagrams, Examine about the Behavioural Diagr...

Examine about the Behavioural Diagrams  The main objective of behavioural diagrams is to visualize, specify, construct and document dynamic aspects of a system. The interactio

Normalization-e-r mapping , Normalize the following table upto and includin...

Normalize the following table upto and including the 3NF. Submit a 1 page printout of only the final set of normalized tables in Data Architect. Just use Data Architect to do the t

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