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Multivalued dependencies are also referred to as tuple generating dependencies. After the Boyce -Codd normal form the results may be devoid of any functional dependencies but it may encounter multivalued dependencies as the multivalued dependencies also cause redundancy of data.
For eg:
If there are 3 attributes involved in a relation,A,B, and C..
Then for every value of A we will have respective values for B and C.. But it is a necessary in the 4th normal form that both B and C values are independent of each other.
This is represented by .,,
A->>B
A->>C..
MVD or Multivalued Dependency is a dependency where one attribute value is potentially a "multivalued fact" about another and the attributes must be independent of each other.
What else can I help you with?
Difference between partial dependency and fully functional dependency?
The difference is that partial dependency is when a database's attribute is only partially dependent on the primary key. Fully functional dependency is when the attribute is entirely dependent on the key.
What is Transitive functional dependency?
A functional dependency X->Y is transitive in R, if there exists an attribute Z in R, such that X-> Z, Z-> Y .
What is Partial functional dependency?
Partial Functional Dependency Indicates that if A and B are attributes of a table , B is partially dependent on A if there is some attribute that can be removed from A and yet the dependency still holds. Say for Ex, consider the following functional dependency that exists in the Tbl_Staff table: StaffID,Name -------> BranchID BranchID is functionally dependent on a subset of A (StaffID,Name), namely StaffID. Source :http://www.mahipalreddy.com/dbdesign/dbqa.htm
What is functional dependency in DBMS?
A key is a set of attributes that uniquely identifies an entire tuple, a function dependency allow us to express constraints that uniquely identify the values of certain attribute.
How can multivalued attributes be handled within the databse design?
Multivalued attributes can be handled in database design by creating a separate table to store the values related to that attribute, establishing a one-to-many relationship with the original table. This new table contains a foreign key that links back to the primary key of the original table, allowing multiple values to be associated with a single record. Additionally, normalization techniques can be applied to ensure efficient data organization and retrieval. By doing this, the database maintains integrity and avoids redundancy.
Is every FD is MVD?
Not necessarily. While every functional dependency (FD) implies a multivalued dependency (MVD), not every MVD is a functional dependency. MVDs involve more complex relationships between attributes compared to FDs.
What is mvd in dbms?
multivalued data
The DBMS can easily handle multivalued attributes?
DBMSs typically do not handle multivalued attributes directly, as they are designed to work with relational data structures that emphasize atomic values. To represent multivalued attributes, a common approach is to create a separate table that links the main entity to its multivalued attributes, ensuring data normalization. This allows for efficient querying and management of related data while maintaining the integrity of the database design.
What is multivalued attribute?
Potential to have more than one value for an attribute
What are some examples of a multivalued attribute?
date of birth determines a person's age.
What is an arcsine?
An arcsine is any of the single- or multivalued functions which are inverses of the sine function.
What is classical logic and multivalued logic?
Classical Logic allows two truth values, True and False. Multivalued or "many-valued logic" allows other kinds of truth values and it allows there to be more than two truth values.
A region that belongs to another state?
Dependency
What is an arccosine?
An arccosine is any of several single-valued or multivalued functions which are inverses of the cosine function.
What is complex attribute in dbms?
Complex Attribute: A complex attribute is an attribute that is both composite and multivalued.
What is an arctangent?
An arctangent is any of several single-valued or multivalued functions which are inverses of the tangent function.
Difference between single valued and multivalued attribute?
single value attribute is one that holds a single value for a single entity. example:- name, roll_number... multivalued attribute is one that holds multiplevalues for a single entities. example:- degree(phd, mca)
