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 inheritance? Define it in detail?
Inheritance
Inheritance can be at the levels of types, or at the level of tables we first consider inheritance of types, then inheritance at the level of labels.
Type inheritance
Assume that we have the following type definition for people
create type person
(name varchar(20)
address varchar(20))
Table inheritance
Create table people of person
The consistency requirements for sub tables are
1. Each tuple of the sub table can correspond to at most single tuple in each of its immediate sub tables.
2. SQL:1999 has an additional constraint that all the tuples corresponding to each other must be derived from single tuple .
multiplicity constarin
What is called a query -execution engine? The query implementation engine takes a query evaluation plan, implements that plan, and returns the answers to the query.
These are the binary operations; i.e., each is applied to two relations or sets. These two relations can be union compatible excluding in case of Cartesian product. Two relations R
Explain CNT in the respects of QBE ? CNT: It is one of the aggregation commands given in QBE. It is used to identify number of tuples
Differance between procedural and non procedural DML? Procedural and non procedural DML Procedural DML exactly what data is require and how to obtain those data. Non procedural
Explain Object oriented Model ? Object Oriented Model - This model is based on the object-oriented programming language paradigm. It involves the features of OOP such as inhe
Synonyms It allows short names or alternative names for objects. Example : CREATE SYNONYM D30 FOR EMPD30; Now if we give command:
Describe Query evaluation engine? Query Evaluation engine: Vehicle executes low-level instructions obtained through the DML compiler. The Storage Manager Components gives in
What is equi join? Equi Join - It generates all the combinations of tuples from two relations which satisfy a join condition along with only equality comparison (=).
external and internal mapping with examples
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