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!
The PROJECT operation
The project operation is used to choose the records with specified attributes as discarding the others based on some related criteria. This is denotes as ∏
(Relation) Example:
Consider the relation PERSON. If you want to display only the names of persons then the project operation will be used as follows:
Π Name (PERSON)
The resultant relation will be as follows:
NAME
Sanjay Prasad
Sharad Gupta
Vibhu Datt
Note: -
1) Π ( Π (R))= Π (R)
As long as have attributes in .
What is conceptual schema? The schemas at the view level are known as subschema that describe dissimilar views of the database.
Question: a) There are three concurrency problems, i.e. three types of potential mistake which could occur if concurrency control is not properly enforced in the database syst
Define shadow paging. An alternative to log-based crash recovery method is shadow paging. This technique requires fewer disk accesses than do the log-based methods.
Problem: A DBMS built for Online Transaction Processing (OLTP) is usually regarded as unsuitable for data warehousing. Each system is designed with a different set of requireme
List two restrictions that are applied on the modification (updation, insertion or deletion) of base tables through view. Ans: The two restrictions are: 1. If a view
Data Mining 1. What is data mining? Write Data Mining applications. 2. Explain OLAP? Write the benefits of OLAP. 3. What are the key features of a Data Warehouse? 4. W
What is a candidate key? Minimal super keys are known as candidate keys.
A video rental company has several branches. The data held on each branch is the branch address made up of street, city, state, and zip code, and the telephone number. Ea
What does the extract statement do in extract datasets? The data is written to virtual memory by extract commands.
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
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