Define multivalued dependency, Database Management System

Assignment Help:

Define multivalued dependency.  What do understand by trivial multivalued dependency? 

Ans: A multivalued dependency is a full constraint among two sets of attributes in a relation. It is differ to the functional dependency, the multivalued dependency needs that certain tuples be present in a relation. Hence, a multivalued dependency is a unique case of tuple-generating dependency. The multivalued dependency plays an important role in the 4NF database normalization.

An MVD X→→Y in R is known as a trivial MVD if (a) Y is a subset of X or (b) X U Y = R


Related Discussions:- Define multivalued dependency

Define the terms- ddl and dml, Define the terms   i) DDL   ...

Define the terms   i) DDL   ii) DML   DDL: Data base schema is specified by a set of definitions expressed by a special   language known as a data def

Types of online analytical processing tools, Describe the various types of ...

Describe the various types of Online Analytical Processing (OLAP) tools and briefly discuss how the support common analytical operations.

What are the different kinds of database end users, What are the different ...

What are the different kinds of database end users? Discuss the major activities of each? End-Users - End-users are the people whose jobs need access to the database for que

What are the causes of bucket overflow in a hash file, What are the causes ...

What are the causes of bucket overflow in a hash file organization? What can be done to reduce the occurrence of bucket overflow? When a record is inserted, the bucket to that

Define null value, Define NULL value NULL value NULL means something is...

Define NULL value NULL value NULL means something is unknown. It does NOT mean null (the digit 0). Null is as well employed as attribute value for a particular entity in which

What are the disadvantages of relational data, What are the disadvantages o...

What are the disadvantages of relational data ? Disadvantages • Performance - If the number of tables among that relationships to be established are large and the tables t

Two types of blocks in the fixed -length representation, What are the two t...

What are the two types of blocks in the fixed -length representation? Define them. Anchor block: Have the first record of a chain. Overflow block: Have the records other tha

Explain hierarchical model, Explain Hierarchical Model ? Hierarchical ...

Explain Hierarchical Model ? Hierarchical Model - It was established to model several kinds of hierarchical organizations which exist in the real world. It uses tree structur

Increased overheads on update-data replication, Increased overheads on upda...

Increased overheads on update : On the drawbacks side, it will need the system to ensure that all replicas of a relation are consistent. This shows that all the replicas of the rel

Define upgrade and downgrade, Define upgrade and downgrade? It gives a ...

Define upgrade and downgrade? It gives a mechanism for conversion from shared lock to exclusive lock is called as upgrade. It gives a mechanism for conversion from exclusive

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd