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!
During the deletion of a tuple two cases can happen:
Deletion of tuple in relation having the foreign key: In this type of case simply delete the desired tuple. For example, in ASSIGNMENT relation we can simply delete the first tuple.
Deletion of the target of a foreign key reference: For instance, an attempt to delete an employee tuple in EMPLOYEE relation whose EMPID is 101. This employee shown not only in the EMPLOYEE but also in the ASSIGNMENT relation. Can these tuple be deleted? If we delete the tuple in EMPLOYEE relation then two unequalled tuples are left in the ASSIGNMENT relation, therefore causing violation of referential integrity constraint. Therefore, the following two choices be for such deletion:
RESTRICT - The delete operation is "restricted" to only the situation where there are no such matching tuples. For instance, we can delete the EMPLOYEE record of EMPID 103 as there is no matching tuple in ASSIGNMENT but not the record of EMPID 101.
CASCADE - The delete operation "cascades" to delete also those matching tuple. For instance, if the delete mode is CASCADE then deleting employee having
EMPID as 101 from EMPLOYEE relation will also make deletion of 2 more tuples from ASSIGNMENT relation.
(a) Data Mining Process : In the context of this cluster analysis project , and in your own words , explain how you would execute the first stage of data mining, namely the "P
What is database Trigger? A database trigger is a PL/SQL block that can explained to automatically execute for insert, update, and delete statements against a table. The trigge
1. Create the tables for the play-scheme database as specified in the TMA. 2. Enter the data as given in the spreadsheet. 3. Create queries to retrieve specified information
In this programming assignment, you will develop a simple database of student records. Here are the requirements: 1) A student record contains a name and a number. We assume tha
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
Write short notes on domain relational calculus The domain relational calculus uses domain variables that take on values from an attribute domain rather than values for whole
Using a labelled diagram explain the operation of the Data Warehouse, define the basic architectural components and outline the main functionalities. Briefly explain the role an op
How does a query tree represent a relational algebra expression? Discuss any three rules for query optimisation, giving example as to when should each rule be applied. Ans
explain equi-join using illustration
Eliminate Columns Not Dependent On Key The Employee Relation satisfies - First normal form - As it has no repeating groups. Second normal form - As it do not have multi-a
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