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 the primary key functions?
Primary Key : The primary key is an attribute or a set of attributes in which uniquely identify a specific example of an entity. Every entity in the data model must have a primary key whose values uniquely recognize instances of the entity.
To qualify as a primary key for an entity, an attribute must have the subsequent properties: * It must have a non-null value for each instance of the entity. * The value must be unique for each instance of an entity * The values must not change or become null during the life of each entity instance.
Normal 0 false false false EN-US X-NONE X-NONE
How Relational Calculus is different from Relational Algebra? What do understand by TRC queries and DRC queries? Ans: Relational calculus contain two calculi, the tuple relati
What is a SELECT operation? The select operation selects tuples that please a given predicate. We use the lowercase letter σ to denote selection.
Structure Of Distributed Database: A distributed database system haves of a collection of sites, each of which keeps a local databases system. Every site is able to process local
Explain the difference between using functions along with and without grouping attributes in relational algebra. Give examples. Ans: Group functions are used to group data of
Consider the 1ollowin8 relation: CAR SALE (Car_id, Option_type, Option_listprice, Sale_date, Option_discountedprice) This relation refers to options installed in cars (e.g., crui
what characterizes the levels in RAID technology
Which model is record based logical model? Network Modelis basically known as record based logical model.
Find a 3NF decomposition of the following relation scheme: University (Faculty, Dean, Department, Chair, Professor, Rank, Student}. The University relation satisfies the following
" Wound-wait" scheme : It is based on a preemptive method. It is based on a simple rule: If Ti requests a database resource that is held by Tj
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