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!
Explain algorithm of ER To Relational Mapping ?
ER-to-Relational Mapping Algorithm:
1) Step 1: Mapping of regular entity types: For each strong entity type E, form a relation T which involves all the easy attributes of a composite attribute.
2) Step2: Mapping of weak entity types: For each weak entity type W along with owner entity type E, create relation R and involve all easy attributes (or simple components of composite attributes) of W as attributed of R. In addition, involves as foreign key attributes of R, the primary key attribute (s) of relation(s) which correspond to the owner(s) and the partial key of the weak entity type W, if any.
3) Mapping of relationship types: form a relation R, for relationship along with primary keys of participating relations A and B as foreign keys in R. Further to this, any attributes of relationship become an attribute of R also.
4) Mapping of multivalued attributes: For every multilvalued attribute A, form a new relation R. This relation R will involve an attribute corresponding to A, plus primary key attribute K-as a foreign key in R-of the relation which represents the entity category or relationship type that has A as an attribute.
Define cardinality and participation constraints on a relationship type, completeness constraint on generalization. Ans: Cardinality defines the number of entities to wh
A constraint named less_than_20 was defined on the field date_of_birth of table student. Delete this constraint. ALTER TABLE student DROP CONSTRAINT less_than_20;
Define DBMS? DBMS: database management system (DBMS) is computer software designed for the reason of supervision databases based on a variety of data models.
Explain the Role of a database administrator a. Defining the Schema The DBA describes the schema which consists of the structure of the data in the application. The DBA
What are the several forms of identity? a) Value b) Name c) Built-in
Design Of Distributed Databases: The distributed databases are mainly relational at local level. So a local database schema is the similar as that of a centralised database design
Consider a systems development project with the following data Activity Duration (weeks) Precedence Relationship 1. Software design
Describe the Composite Key Composite Key: Sometimes one key is not enough to uniquely recognize a row. E.g. in a single class Roll is enough to search a student, but in the w
Homework chapter 10 no 3
Need for Client Server Computing- Client/Server (C/S) architecture includes running the application on multiple machines in which every machine with its component software tackles
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