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!
Describe logical data independence ?
Logical Data Independence - It is the capacity to modify the conceptual schema without having to change external schemas or application programs. The conceptual schema might be changed to expand the database (through adding a record type or data item), to change constraints, or to decrease the database (by removing a record type or data item). Only the view definition and the mappings required are changed in a DBMS that supports logical data independence. Changes to constraints could be applied to the conceptual schema without moving the external schemas or application programs.
What is meant by functional dependencies? Consider a relation schema R and α C R and β C R. The functional dependency α ->β holds on relational schema R if in any legal relati
How can you map NULL values to other values while display? IF( ) , IFNULL( ) keywords are used to do so. They are 'LIMIT' is used for the following kinds of problems: 1) Ans
Explain Growing Phase of locking Growing Phase: In this phase the transaction can only obtain locks, but cannot release any lock. The transaction enters the growing phase as so
Given the following relations TRAIN (NAME, START, DEST) TICKET (PNRNO., START, DEST, FARE) PASSENGER (NAME, ADDRESS, PNRNO.) Write SQL expressions for the following queries: No
What do you understand by RAID? Explain RAID Level 4 and Level5? RAID - It is stands for Redundant Array of Inexpensive Disks (as named by the inventor), or alternatively Re
What are the two types of errors? The two types of errors are: a) Logical error b) System error
Scenario 1: Power goes out after the first instruction. What happens?
What is conceptual model ? A conceptual model is a independent of both hardware and software.
Question 1 List and explain various Normal Forms. How BCNF differs from the Third Normal Form and 4th Normal forms? Question 2 Describe the concepts of Structural Semantic Da
Explain the two constraints, check and foreign key in SQL along with an example for each. Give the syntax. CHECK constraint - CHECK constraint specifies an expression which
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: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd