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.
why data in an RDMS need to be normalised
Key to represent relationship amongs tables is called ? A Key that represent the relationship between tables is called Foreign Key.
Write short notes on relational constraints? Relational Constraints are: 1. NOT NULL 2. Unique 3. Primary key 4. Foreign key 5. Table check
Explain data dictonary on oracle ? Data Dictionary - Data dictionaries are the system tables in which contain descriptions of the database objects and how they are structured.
Ask q“A database will be made to store information about patients in a hospital. On arrival, each patient’s personal details (name, address, and telephone number) are recorded wher
The natural join is equal to which product? The natural join is equal to Combination of projection and Cartesian product
One-way Associations If an association is only traversed in single direction, then it is known as one-way association. It is implemented as a pointer or an attribute which con
why are older data base model are being replaced by new data model
Example : Create a sequence named SEQSS that starts at 105, has a step of 1 and can take maximum value as 2000. CREATE SEQUENCE SEQSS START WITH 105 INCREMENT BY 1 MAX VA
For the relations answer the following queries in SQL Street (name, location, city) House (number, street_name) Lives (name, house_number) (i) Obtain the names of persons who liv
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