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!
Discuss the types of integrity constraints in which must be checked for the update operations - Insert and Delete. Give examples.
Insert operation can violet any of the subsequent four constraints:
1) Domain constraints could be violated if given attribute value does not appear within corresponding domain. 2) Key constraints could be violated if given attribute value does not appear within corresponding domain. 3) Entity integrity can be violated if the primary key of the latest tuple t is NULL. 4) Referential integrity can be violated if value of any foreign key in t refers to a tuple in which does not exist in referenced relation.
Delete operation can violate only referential integrity constraints, if the tuple being deleted is referenced through the foreign keys from other tuples within the database.
What is key ? Key - A single attribute or a combination of two or more attributes of an entity set which is used to recognize one or more instances (rows) of the set (table) is
List the set operations of SQL? 1) Union 2) Intersect operation 3) The except operation
Draw and explain the three level architecture of the database system? A DBMS gives three levels of data is said to follow three-level architecture. The trget of the three-schem
Define reference file
Types of Locks There are two necessary types of locks: Binary lock : This locking mechanism has two states for to a data item: locked or unlocked Multiple-mode loc
After going by the database architecture, let us now dwell on an important query: how is the data organised in a database? There are a lot of basic structures that exist in a datab
Objectives After reading this part, you should be able to: Modify, create, and delete database schema objects; Update database using SQL command; Retrieve data f
statical data
Deadlock Prevention One of the easiest approaches for avoiding a deadlock would be to obtain all the locks at the begin of the transaction. Though, this approach restricts conc
(a) Why did SAP introduce the extended star schema?
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