Define candidate key, alternate key, composite key?

Answer Posted / ramesh

A composite Key can be either Primay or Unique Key
More then One Key columns are said to be composite keys

Candidate Key(Primary Key) is a Key which Maintains the Row
Uniue .Can be defined based on the Entity


Alternate Key or Unique Key is similar to PK ,except it
accepts null Values .So that the records can still be
entered submitting null values to this attribute.

Is This Answer Correct ?    151 Yes 207 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

Hi , any one can help me on the same,this is regarding the Informatica Function doc,i want to know how developer is will develop the mapping. pl forwar the any function doc .just for my references. svlc75@yahoo.co.in

1585


What is data modeling with example?

530


I have a few records all are same structures data, I want to store data in multiple targets how

2142


Explain about query and reporting.

1688


How would you design a database for an online site, which would average a million hits a day?

576






Write short notes on manual refreshes.

2290


Explain about the database management systems.

568


What is normalization? Explain different levels of normalization?

59817


Explain about relational operator join?

614


Explain about the relational database?

608


Explain about a primary key?

572


What is dbms and its application?

554


Can an extended stored procedure be called from inside a user-defined function?

610


What is the physical representation for a many-to-many relationship?

576


You are testing the performance of a query the first time you run the query, the performance is slow. the second time you run the query, the performance is fast. why is this?

525