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)
What are the purpose for having variable length records? What kinds of separator characters are required for each? Variable-Length Records - Variable-length records are thos
It is mandatory that for every table in the LDB hierarchy there should exist one GET statement in the report. False. It is not essential.
Define various ways in which SELECT statement can be used for record selection Technology? SELECT gives you control over a number of aspects for record retrieval: 1) Which
To delete a particular column in a relation which command is used ? To delete a particular column in a relation ALTER command is used.
Create student database and retrieve course name taught by king? STUDENT (name, student#, class, major) COURSE (course name, course#, credit hours, department) SECTION (secti
First Normal Form and second normal form First Normal Form (1NF) A relation is said to be in 1NF if it having no non-atomic values and each row can give a unique combinat
Farmer Bob, Farmer Jane and Farmer Jose run a cow farming co-op. For every cow they keep the cow’s name, age (or date of birth), breed and numbered plastic ear tag. The each of t
What is a primary index? A primary index is an index whose search key also explains the sequential order of the file.
Can a stored procedure call itself or recursive stored procedure? How much level SP nesting is possible? Yes. Because Transact-SQL supports recursion, you can write kept proced
State your technical objectives for mining the data. Data Understanding. Describe the data For each attribute, give its description and data type. For numeric attributes
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