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.
What are the types of reference?explain it with suitable examples? Object oriented language given the ability to refer the object attribute of the type can be referred to the s
Define physical image of a global relation at a site
How can we Classify the operations on classes This step fundamentally means all three models functional, object and dynamic (studied in last section) must be combined so that
external and internal mapping with examples
What do you mean by DBMS? What is its need and what are its goals. Explain? OR Explain Data Base Management System? Sol. Database management system is a
Backward Recovery (UNDO): In this system the uncommitted changes made by a transaction to a database are undone. Instead the system is reset to the last consistent state of databa
Critically evaluate the bulleted list of information-related items in this case study. How are each contradictory to the notion of being an information-literate knowledge worker?
For problems 1-4, give all candidate keys for the tables with FDs specified. Composite candidate keys must be put in parentheses, and candidate keys must be separated with commas
A distributed transaction consists of subtransactions that execute at different sites and access local DBMSs at those sites. For example, a distributed transaction that transfers m
A field-groups statement or an insert statement reverses storage space and transfers values. False.
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