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.
Update or Modify operation alters the existing values. If these operations alter the value that is the foreign key also, the only check need is the similar as that of the Insert op
This project requires you to create a database design. Your design will be documented in a set of Entity-Relationship diagrams. Draw a set of Entity-Relationship diagrams to mode
Describe log based recovery The most usably structure for recording data base modification is the LOG the log is a sequence of log records recording all the update activities i
#question.ERD of any car
Explain What is Relation? A database relation is a predefined row or column format for storing information in a relational database. Relations are equal to tables.
explain three types of internet risks to the consummers whent he business system is data dependent. how can we minimise these risks
Retrieve the S&S In-Chapter Database (in Microsoft Access format) from the text's Web site (or create the tables in Table 4-5 in a relational DBMS product). Write queries to answer
Using your cache simulator and using smalltex.din as your memory trace determine the total miss rate, compulsory miss rate, capacity miss rate, and conflict miss rate for the follo
#quesDefine a job scheduling strategy that will meet business requirement of reporting availability by 6am CST for the following cubes? Show the job scheduling dependencies in a pi
What is called query processing? Query processing refers to the range of activities included in extracting data from a database.
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