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!
Differentiate between logical database design and physical database design. Show how this separation leads to data independence?
Basis
Logical Database Design
Physical Database Design
Task
Maps or transforms the conceptual schema (or an ER schema) from the high-stages data model into a relational database schema.
The specifications for the stored database within terms of physical storage structures, record placement, and indexes are designed.
Choice of criteria
The mapping can proceed in two levels:
1. System independent mapping but data model-depending.
2. tailoring the schemas to a specific DBMS.
The following criteria are frequent used to guide the choice of physical database design option:
1. Response Time option
2. Space Utilization
3.Transaction throughout
Result
DDL statements within the language of the chosen DBMS that specify the conceptual and external stages schemas of the database system. But if the DDL statements involve a few physical design parameters, a completed DDL specification must wait until after the physical database.
An initial determination of storage structures and the access paths for the database files. This corresponds to defining the internal schema in terms of Data Storage Definition Language.
The database design is separated into various phases. The logical database design and physical database design are two of them. This separation is commonly based on the concept of three-level architecture of DBMS that gives the data independence. Therefore, we can say in which this separation leads to data independence since the output of the logical database design is the conceptual and external level schemas of the database system that is independent from the output of the physical database design which is internal schema.
1. Determine the set of minimal functional dependencies for the following data. The local bakery, Happy Cakes, needs your help designing a database that will support a kiosk in
Creating views with Read only option : In the view definition this option is used to make sure that no DML operations can be done on the view.
to develop elrctronic database from manual forms
List two restrictions that are applied on the modification (updation, insertion or deletion) of base tables through view. Ans: The two restrictions are: 1. If a view
System error :These contain errors in database system or the OS, example, deadlocks.Such errors are fairly hard to detect and need reprogramming the erroneous components of the sys
Key to represent relationship amongs tables is called ? A Key that represent the relationship between tables is called Foreign Key.
What is a database? At any given time, they're storing a tremendous amount of information - inventory, in the case of Amazon, messages and interrelationships in the case of Tw
what is query processing ,query optimization and performance turring?
What are shortcomings in structured approach? Structured methodology treats data and their behaviours separately, and this makes it harder to isolate changes. If changes are re
Explain how the associations are implemented as classes. A general approach in this case is to transform an association class into a simple class linked to two original classes
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