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!
Define the Query optimisation
The query parser commonly generates a standard initial tree to correspond to an SQL query, with no doing any optimization. Such type of a canonical query tree denotes a relational algebra expression that is extremely inefficient if executed directly. A query commonly has many possible execution strategies, and the process of choosing a appropriate one for processing a query is termed as query optimization. The major guidelines that are applied throughout query optimization are:
a. Combine a cascade of selections
b. Combine a cascade of projections
c. Commute selection and projection
d. Commuting selection with join / cartesian product Commuting projection with join or cartesian product
e. Commute projection with set operations
f. Commute selection with set operations
Explain the following functions of Oracle with suitable examples: (i) To_Char( ) (ii) Count( ) (iii) Trim( ) (iv) Length( ) Ans: (i) To_char( ): The TO_CHAR function conver
Consider the following six relation schemes and their corresponding sets of functional dependencies. In each case identify a. All the candidate keys b. The highest normal for
Describe the primary key functions? Primary Key : The primary key is an attribute or a set of attributes in which uniquely identify a specific example of an entity. Every entit
What is conceptual schema? The schemas at the view level are known as subschema that describe dissimilar views of the database.
How can you connect to the MySQL Server? In order to connect to the MySQL server it is necessary to give the username and password so this be able to done with The following
What are composite objects? Objects that have other objects are known as complex objects or composite objects.
Define Direct file organization? The direct file organization is employed to enhance the performance in accessing the records than sequential file organization. In direct file
MOSS VALE is a town with 15000 inhabitants. The fire department wishes to develop a system that automates the despatch of fire engines to attend fires. The ERD below describes the
Demonstrate your knowledge of PL/SQL programming by writing and thoroughly testing triggers and stored procedures associated with an e-commerce application that provides security l
We will explain here an example database application having COLLEGE database and use it in showing several E-R modelling concepts. College database remains track of faculty, Stu
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