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.
Describe sequential file organization. Explain the rules for (i) Inserting a new record. (ii) Deleting an existing record. Ans:A sequential f
I want to buy this but I want to see a couple sample questions first. http://www.expertsmind.com/library/what-happens-to-rms-error-for-the-training-data-set-51564843.aspx
Define and differentiate between ordered indexing and hashing. Ans: Ordered indexing: To gain fast random access to records in a file, we can make of an index structure. Every
explain thee diffrent types of data models
Data Handling and Research Methods: The dataset encompassing 130 participants contains several variables measuring detrimental health related behaviours referring to the use o
Consider the entity type dependent related to employee entity, which is used to keep track of the dependents of every employee. The attributes of dependents are: name, sex, birth d
Can you scan double-sided documents - and remove blank pages? Our software and imaging systems supports duplex scanning, at the same time scanning both sides of a page. Program
Creating views with check option : This option limits those updates of data values that cause records to go off the view. The following instance tells this in more detail: Examp
wh
Define average latency time. The average latency time of the disk is one-half the time for a full rotation of the disk.
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