Fds in relationships and teaches relationship, Database Management System

Assignment Help:

FDs in Relationships:

 Enrols Relationship: None as it is many to many

Teaches Relationship: Course code → Instructor

Instructor → Course code

The next question is:  How do we recognize the functional dependence in a database model?

Functional dependencies occur from the nature of the actual world that the database models. Often A and B are facts about an entity where A may be some identifier for the entity and B some characteristic. Functional dependencies cannot be automatically determined by studying one or more cases of a database. They can be determined only by a careful study of the actual world and a clear understanding of what every attribute means.

 There are no thumb rules for determining FDs.

Functional dependence is an vital concept and a large body of formal theory has been developed about it.

 


Related Discussions:- Fds in relationships and teaches relationship

In which relational modes cardinality is termed, In which relational modes,...

In which relational modes, cardinality is termed? Answer : Cardinality is termed in a number of tuples relational modes.

Ways to suggest the dba, a)  Suppose we updated the catalog tables in real ...

a)  Suppose we updated the catalog tables in real time, that is, after every update, insert, or delete SQL statement were executed-rather than only running RUNSTATS once every few

Data mining, 1.Why we need data mining? Give an example to illustrate your ...

1.Why we need data mining? Give an example to illustrate your answer. 2. Why data mining is considered as "misleading name"? 3. Distinguish the difference between database an

Example of grant create session to mca12, Example -GRANT CREATE SESSION TO ...

Example -GRANT CREATE SESSION TO MCA12; (This command gives system level permission on creating a session - not portable) GRANT SELECT ON EMP TO MCA12; (Object level permi

What are the uses of odbc, What are the uses of ODBC? Under what circumstan...

What are the uses of ODBC? Under what circumstances we use this technology? ODBC expose database capabilities within a standardized way to the application programmer by an ap

Case study, what problems are raised by the database? why is it so controve...

what problems are raised by the database? why is it so controversial? why is data quality an issue?

What are the situations while dbms should not be used, What are the situati...

What are the situations while DBMS should not be used? DBMS should not be used in situations like: (i) No need of security. (ii) Not difficulty to access the data (iii) N

Advantages and disadvantages of using a database system, What are the advan...

What are the advantages and disadvantages of using a database system. Sol. Advantages of Database System (DBMS) :  (1) Data Redundancy and Inconsistency: Since differen

Update operations in dbms - insert operation, Update Operations and Dealing...

Update Operations and Dealing with Constraint Violations There are three basic operations to be executes on relations: Insertion Deletion Update The INSER

Advantages of database systems, Problem 1. Describe the following a)...

Problem 1. Describe the following a) Advantages of Database Systems b) Functions of a DBMS Explanation of part (a) and (b) 2. Explain the following concepts w

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