Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Transactions And Concurrency Management
Introduction
One of the main benefits of storing data in an integrated repository or a database is to permit sharing of it between multiple users. Various users access the database or perform transactions at the similar time. What if a user's transactions try to access a data item that is being used /modified by another transaction? This unit attempts to give details on how concurrent transactions are implemented under the control of DBMS. Though, in order to describe the concurrent transactions, first we must explain the term transaction.
Concurrent implementation of user programs is essential for good performance of DBMS, as concurrent running of various user programs keeps utilizing CPU time efficiently, as disk accesses are frequent and are relatively slow in case of DBMS. Also, a user's program may carry out a lot of operations on the data returned from DB, but DBMS is only concerned about what data is being written from / read / into the database.
Find out the names and company names of all employees sorted in ascending order of company name and descending order of employee names of by which company. SELECT EMPLOYEE_NAME,
Consider a bank that has a collection of sites, each running a database system. Suppose the only way the databases interact is by electronic transfer of money between one another,
Describe entity referential integrity and integrity. Give an example of each. Entity Integrity Rule - If there is a attribute A of relation R is a prime attribute of R then A
Explain the integrity constraints: Not Null, Unique, Primary Key with an example each. Is the combination 'Not Null, Primary Key' a valid combination. Justify. Not Null - Shou
One-way Associations When an association is traversed only in the one direction, then it is implemented as a pointer i.e.an attribute which contains an object reference. If mu
Describe the difference between a one-to-many and a many-to-many relationship. Which logical data structures comprise one-to-many and which comprise many-to-many relationship?
What is transaction? Collections of operations that form a single logical unit of work are known as transactions.
State about the Use Case Diagram A use case diagram represents a set of use cases, actors and their relationships. These diagrams shall be used to model context or requirement
While sorting, if the main storage available is not enough, the system writes data to an external help file. The SAP profile parameter, which determines DIR_SORTTMP
What is a guard condition? Explain it with a suitable example. The guard-condition is a Boolean expression written with respect to parameters of triggering event and attributes
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd