waht is the difference between primary key and super key?
Answer Posted / sweety singh
superkey is a set of attributes that can uniquely identify
individual tuples whereas a key or a primary key is a
minimal super key that can identify individual tuples.
ex..eno pno hrs
1 1 2
2 4 7
i.e...here eno,pno,hrs together are a superkey but eno,pno
is primary key and hence eno,pno cant hav null values and
repeated enteries....
Is This Answer Correct ? | 8 Yes | 3 No |
Post New Answer View All Answers
how to do daily transactions with out sql* loader control file regesterd in apps?
What is the fastest query method to fetch data from the table?
Why we use bulk collect in oracle?
Give the constructs of a package, function or a procedure.
How to run create database statement again?
How to select some columns from a table in oracle?
What are dml statements in oracle?
How to Truncate Table in Oracle
Explain an index?
Is oracle an operator?
What are the arithmetic operations?
How do you get nicely formatted results from an oracle procedure that returns a reference cursor?
Is java required for oracle client?
What is hot backup and logical backup?
Explain what are synonyms used for?