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.
Discuss the methods for a hash file to expand and shrink dynamically. What are the advantages and disadvantages of each? The hashing methods that permit dyanamic file expansi
write a short note on participation role? Participation role: roles are indicating in E-R diagram by labelling the lines that connect diamonds to rectangles.
design a generalization specialization hierarchy for a motor vehicle sales company. the company sells motorcycles, passenger cars, vens and buses.
Define multivalued dependency. What do understand by trivial multivalued dependency? Ans: A multivalued dependency is a full constraint among two sets of attributes in a rela
1. Create a subroutine that does the remote blast on the file protein.fa. 2. Pass that returned files from the blast to another subroutine that parses the output and sends it to
sir, could anybody help me in getting complete information about the mentioned topic
milestone assignment
What are ways of finding out either an update is required or not for derived attributes? The ways to find out an update is required or, not are as: Explicit update
Hierarchical model is also known by? A hierarchical model is also known as a Tree structure.
Q. Define a weak entity set and its identifying relationship. List the necessary conditions for a meaningful identifying relationship set of a weak entity set. Entity is a t
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