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!
Define physical and logical data independence. How does this architecture help in achieving these?
Data independence entails that change in one view must not need a change in the view(s) above. There are two sorts of data independence: logical and physical. The meaning of Logical data independence is that the conceptual view can be changed without influencing the existing external view, that is a given record may be spilt or combined along with other records but the external views need not be modified to reflect this. The meaning of Physical data independence is that the physical storage structures or devices employed to store the data can be changed without effecting the existing conceptual view or external view, that is if earlier indexed sequential files are employed to store data and then the B- trees are used, even then the upper layers must not be effected.
When are they useful? Justify with an example. The temporary tables are commonly used to support specialized rollups or exact application processing needs. Unlike a permanent t
The technique of converting the state diagram to code a) Identify all major control paths. Start from initial state; choose a path across the diagram that corresponds to normal
Describe an data dictionary? A data dictionary is a data structure which keeps meta data about the structure of the database ie. the schema of the database.
List any two disadvantages of a database system ? The disadvantages of database system are: • Database systems are difficult, complex, and time-consuming to design. • Substanti
Redo Logs: Any database must have minimum two redo logs. These are the rules for the database; the redo logs record all modifies to the system objects or user objects. If any type
Draw an Entity-Relationship model for the relational schema given in the Appendix. Show all the entities, relationships, relationship names, and attributes and also underline the
What are the costs to be considered when a transaction has to be rolled back when recovering from deadlock? Ans: A few transaction will must rolled back (made a victim)
Describe briefly models which define the operations on classes. The three models which are used to define operations on classes are as: Object Model = data dictionary + Obje
What is transaction? Collections of operations that form a single logical unit of work are known as transactions.
OBJECTIVES After going through this unit you should be capable to: Explain the File Based system and its limitations; Explain the structure of DBMS; Explain the
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