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!
What are partial, alternate,, artificial, compound and natural key?
Partial Key: It is a set of attributes that can uniquely recognize weak entities and that are related to same owner entity. It is sometime known as Discriminator.
Alternate Key: All Candidate Keys excluding the Primary Key are called as Alternate Keys.
Artificial Key: If no obvious key either stands alone or compound is available, then the last resort is to simply make a key, by assigning a unique number to every record or occurrence. Then this is known as developing an artificial key.
Compound Key: If no single data element uniquely identifies occurrences within a construct, then combining multiple elements to make a unique identifier for the construct is known as creating a compound key.
Natural Key: When one of the data elements stored within a construct is utilized as the primary key, then it is known as the natural key.
Explain the steps for reduction of E-R model into relational model. Ans:(a) Entity set in E-R model will be considered as table name in relational Model. (b) Attributes of e
Mappings between Levels and Data Independence The 3 levels of abstraction in the database do not exist separately of each other. There must be some correspondence, or mapping
Example: //REVOKE ALL ON EMP FROM MCA12; (All permissions will be cancelled) You can also cancel only some of the permissions. Drop: A user-
You are required to design and build a data mart/data warehouse using Oracle. A national bank allocates funding every year for its local branches to provide temporary staff cove
Your OS has a set of queues, each of which is protected by a lock. To enqueue or dequeue an item, a thread must hold the lock associated to the queue. You need to implement an a
Properties of a Transaction A transaction has four main properties. These are: Atomicity Consistency Isolation or Independence Durability or Permanen
Storage Of Database On Hard Disks At this point, it is worthwhile to note the difference among the terms file Organisation and the access method. A file organisation shows to t
The JOIN operation is applied on two relations. When we want to choose related tuples from two given relation join is used. The join operation need that both the joined relations m
Explain the structure of well formed formulae in relational calculus. Ans: a. An atom is a formula b. If P1 is a formula, after that so are ¬P1 and (P1) c. If P1 and P2 a
Why is database design important?
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