Shared lock or read lock, Database Management System

Assignment Help:

Shared lock or Read Lock

  • It is requested by a transaction that needs to just read the value of data item.
  • A shared lock on a data item does not permit an exclusive lock to be placed but allows any number of shared locks to be placed on that item.

 


Related Discussions:- Shared lock or read lock

Explain alternate key, Explain Alternate key? Alternate Key - All the...

Explain Alternate key? Alternate Key - All the candidate keys except primary key are known as alternate keys.

Implementation of association as an object, Implementation of association a...

Implementation of association as an object Implement as a separate association object, independent of either class, as in Figure. An association object is a group of pairs

Rules of data normalisation, Rules Of Data Normalisation  Let us now su...

Rules Of Data Normalisation  Let us now summarise Normalisation with the help of various clean rules. The following are the necessary rules for the Normalisation process: 1.

What are the different types of interfaces provided by dbms, Question 1 Su...

Question 1 Suppose the employee employee id, name, designation, salary, attendance and address of any employee has to be stored in a database. You can store these data in a sequen

Define thomas write rule, Define Thomas write rule Thomas' write rule: ...

Define Thomas write rule Thomas' write rule: The Thomas' write rule is a modification of timestamp-ordering protocol for concurrency control. Assume that transaction T i issue

What is system catalog or catalog relation, What is system catalog or catal...

What is system catalog or catalog relation? How is better known as? A RDBMS maintains a explanation of all the data that it contains, information about every relation and index

Define the canonical cover, Define the Canonical cover Ans: A canonical...

Define the Canonical cover Ans: A canonical cover F c for F is a set of dependencies like F logically implies all dependencies in F c , and F c logically entails all dependen

Give an expression within sql for queries, Consider the following relations...

Consider the following relations:  S (S#, SNAME, STATUS, CITY)  SP (S#, P#, QTY)  P (P#, PNAME, COLOR, WEIGHT, CITY) Give an expression within SQL for each of queries b

Find names of employees, Consider the relations EMP(ENO,ENAME,AGE,BASIC_S...

Consider the relations EMP(ENO,ENAME,AGE,BASIC_SALARY) WORK_IN(ENO,DNO) DEPT(DNO,DNAME,CITY) Express the following queries in SQL (i) Find names of employees who work in a dep

Why we use delegation to share implementation, Use Delegation to Share Impl...

Use Delegation to Share Implementation The delegation " Delegation comprises of catching an operation on one object and sending it to other object which is part, or related to

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