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!
Views in relational algebra:
1. Basic expression contains either
a) A relation in the database.
b) A constant relation.
2. General expressions are madde out of smaller sub expressions using
a) σp(E1) select (p a predicate)
b) ∏s(E1) project (s a list of attributes)
c) Px(E1)rename (x a relation name)
d) E1∪E2 union
e) E1- E2 set difference
f) E1x x E2 cartesian product
Define NULL value NULL value NULL means something is unknown. It does NOT mean null (the digit 0). Null is as well employed as attribute value for a particular entity in which
What is called mirroring? The simplest approach to introducing redundancy is to duplicate each disk. This method is called mirroring or shadowing.
What is a disjoint less constraint? Ans: It needs that an entity belongs to no much more than one level entity set. Disjoint less constraint needs that an entity belongs to
Question: (a) Why is it important to know the architecture rather than to start requirement capture when designing a large scale system? (b) Who are the different people in
what is definition hierarchical data model
Add generation capabilities and/or tailor the built-in functionality of generator. This enables you to produce "all" the test data for the MySQL tables you produced in the previous
Define a relation ? Relation - A relations is a named two-dimensional table of data. Mathematically, a relation can be described as a subset of the cartesian product of a lis
Implementation of association as an object Implement as a separate association object, independent of either class, as in Figure. An association object is a group of pairs
Discuss how the one-to-one associations have to be implemented. Some of properties of associations can be implemented directly by providing suitable declarations of the data me
define locking in simple language and decribed it
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