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 entity integrity and referential integrity. How does SQL allow specification of these?
Ans: Entity Integrity Rule- If the attribute A of relation R is a prime attribute of R after that A cannot accept null values.
Referential Integrity Rule- In referential integrity, it is made sure that a value that appears in one relation for a given set of attributes as well appears for a particular set of attributes in another relation.
In SQL, referential integrity and entity integrity rules are implemented as constraints on the relation known as reference Key constraint and primary Key constraint correspondingly.
These constraints can be fixed with relation at the time of creation of the relations or after the creation of the relations by altering the definition of the relations. For instance:
Relationship between Security and Integrity: Database security usually refers to access, while database integrity refers to avoidance of accidental loss of consistency. But usually
In tuple relational calculus P1 → P2 is equivalent to ? A In tuple relational calculus P1→ P2 is equivalent to ¬P1 V P2. (The logical implication expression A B, meaning
Explain what is Aggregation? Aggregation: Aggregation is an significant concept in database design whereas composite objects could be modelled during the design of database a
Explain the Static or conservative Two Phase Locking: Static (or conservative) Two Phase Locking: In this type of scheme, all the data items are locked earlier than any opera
Prepare a gantt chart for the stock control project: Scenario Lucas-TVS is the Leader in Auto Electricals in India today with 50 years experience in desig
need a DBMS system on any data for assignment.
Define seek time. The time for repositioning the arm is known as the seek time and it enhances with the distance that the arm is known as the seek time.
What are the different integrity constraints in RDBMS? The various integrity constraints in RDBMS are as: Primary Key: primary key is a grouping of one or more attributes
It can be easily defined as: The database must not have any unmatched foreign key values. The term "unmatched foreign key value" means a foreign key value for which there doe
Question: One of the tasks a database management system must perform is to ensure that the data is still intact in the face of software and hardware failure. This task is known
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