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!
Define the basic operations of the relational algebra?
Ans: Basic operators of relational algebra are:
1. Union (∪) - Selects tuples which are in either P or Q or in both of them. The duplicate tuples are removed.
R = P ∪ Q
2. Difference or Minus (-) - eliminates common tuples from the first relation.
R = P - Q
3. Cartesian Product or Cross Product (×) - The cartesian product of two relations is the concatenation of tuples that are belonging to the two relations and containing all possible combination of the tuples.
R = P× Q
4. Projection (π) - The projection of a relation is illustrated as a projection of all its tuples over some set of attributes that is it yields a vertical subset of the relation. The relation's projection T on the attribute A is presented by T [A] or πA(T),.
5. Selection (σ) - Selects just some of the tuples, those satisfy specified criteria, from the relation. It yields a horizontal subset of a following relation.
R = σB(P)
Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4
What is inheritance? Inheritance is an object orientation concept that allows reusability of code / design. Basic sense of inheritance is that if one class is predefined than a
i want answers this assignment now if yiu can maket for me now ?
What is system log? What are the entries? Ans: The system log that is generally written on stable storage contains the redundant data required to recover from volatile
Project: Microsoft Access You have been asked by the ABC Tanning Salon to create a database that can be used to track the salon's customers. You are to create a table in Access
As with other software, databases can potentially be used for unethical purposes. As a database developer, and a consumer, you should recognize database misuse, and how it may affe
I need a professional to prepare a database to collect and store basic information. The information can be basic info such as contact details etc. One requirement i have is f
Attributes having a one value for a particular entity. For instance, Age is a single valued attribute of a student entity. Attributes that have more than single values
Explain the database Planning Project ?
What is the use of group by clause? Group by clause is used to apply aggregate functions to a set of tuples. The attributes given in the group by clause are used to
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