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!
What is data model? Explain object based and record based data models?
Ans: A data model is an abstract model in which describes how data is represented and accessed.
(i) Object based data models: Same to a relational database model, but objects, classes and inheritance are directly supported within database schemas and in the query language
(ii) Record based data models: is a database model based on first-order predicate logic. Its core idea is to elaborate a database as a collection of predicates over a finite set of predicate variables, describing constraints on the possible values and combinations of values.
What is relationship instance ? Relationship Instance - A relationship is a relation between two or more entities. An instance of relationship set is a set of relationships.
what is inverted and multilist structure
Explain the EXISTS and UNIQUE functions of SQL. Give an example for each? EXISTS: The EXISTS function takes one parameter that is a SQL statement. If any records exist which
describe all the tables you have created. ?get table_name, status, num_rows, user_stats in user_tables system view ?get table_name, constraint_name, constraint_type in user_constr
What is a SELECT operation? The select operation selects tuples that please a given predicate. We use the lowercase letter σ to denote selection.
What functions does a data dictionary perform? In a (DBMS)data management system, the principal functions performed by the data dictionary are Management of data defini
QUESTION (a)(i) Define the term database. (ii) How is it different from a database management system? (b) What is the difference between an entity and an attribute? (c
Increases efficiency : Data is stored close to most often used site, therefore retrieval would be faster. Also, data that is not required by local applications is not stored, there
Complexity : A distributed DBMS that is available, reliable, and secure is inherently more difficult than a centralised DBMS. Though, adequate data replication is essential to have
Let consider the given partial relation EMP. Let us make some sub-queries for them EMPNO ENAME JOB SAL DEPTNO 7566
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