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.
What is a B+-Tree index? A B+-Tree index takes the form of a balanced tree in which each path from the root of the root of the root of the tree to a leaf of the tree is of the
Explain trigger? Trigger: A database trigger is procedural code which is automatically executed within response to certain events on a particular table in a database. Trigger
Compare wait-die deadlock prevention scheme with wait-wound scheme Ans: Wait-Die Scheme a) Based upon a nonpreemptive technique. b) If Pi requests a resource present
Part: Recommended (Non-query) Optimisations This section entitled "Recommended (non-query) optimisations" should be a brief report containing recommended optimisations you would
PHYSICAL DBMS ARCHITECTURE The physical architecture defines the software components used to process and enter data, and how these software components are related and interc
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
Explain Network Model in DBMS? Network Model - It was formalised within the late year of 1960s through the Database Task Group of the Conference on Data System Language (DBTG
how draw er diagram
#question.ERD of any car
What is a hashing function? What are the properties of a good hashing function? Describe the folding technique for hashing functions. Ans: Hashing function is a method
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