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.
Ask question #MinimRead Dennis et al. Chapter 6: Minicase 2. Work through it and answer the questions. See the attached example. SequenceDiagram.png Based on the structural mod
Illustrate the class diagram for class room scheduling system If in any college, the number of classrooms are limited which have to be allocated to various classes and instruct
Define Radix conversion method One clever way to transform binary numbers to BCD notation (binary-coded decimal) is the "double dabble algorithm". It can be adapted to transfo
What is horizontal fragmentation? Horizontal fragmentation divides the relation by assuming every tuple of r to one or more fragments
What is trigger? Triggers are statements that are executed automatically by the system as the side effect of a modification to the database.
What is the use of group by clause? Group by clause is used to apply aggregate functions to a set of tuples. The attributes given in the group by clause are used to
complete assignment on the above title.
Problem 1 Why are the operational system keys not recommended for forming data warehouse primary keys? Give any two examples 2 Explain the following performance tuning techn
Horizontal Fragmentation- Horizontal fragmentation groups together the tuples in a relation that are collectively used by the main transactions. A horizontal fragment is produced b
What are the authentication modes in SQL Server? How can it be changed? Windows mode and Mixed Mode - SQL and Windows. To alter authentication mode in SQL Server click Start, P
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