What Is Super Key In Dbms?

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12 Answers

Nanju Profile
Nanju answered
A superkey is a combination of attributes that can be uniquely used to identify a database record.With primary key if any other attribute is added then
that combination is called super key in other words,primary key is the minimum
possible super key.in the student table student_no+student_name is one the
super key.
Anonymous Profile
Anonymous answered
If we add additional attribute to a primary key the resulting combination would still uniquely identify as instance of entity set, this augumented key are called super key
Eg. Roll no and name
Anonymous Profile
Anonymous answered
A super key  is the set of one or more attribute that allow us to identify uniquely entity in an entity set.
E.g the customer_id attribute of the entity set customer is sufficient to distinguish one customer entity from another.
Anonymous Profile
Anonymous answered
A column or set of columns that uniquely identifies a row within a table.
Anonymous Profile
Anonymous answered
A Super Key is a of attributes that collectively identify a entity in a entity set. For example, the bank account number is a super key in the bank accounts table.

From Malaysia
Anonymous Profile
Anonymous answered
An attribute or a sets of attribute that uniquely identified an entity in the entity type called a  super key.
Anonymous Profile
Anonymous answered
An attribute or set of attributes, that can identify uniquely in a given relation - SUPER KEY.
An attribute alone that can identify uniquely in a relation is called Primary Key.
There can be several key's in a given relation, that can be identified uniquely. Those can be called Candidate keys.
Rinav Gangar Profile
Rinav Gangar answered
Superkey - A superkey is defined in the relational model as a set of
attributes of a relation variable (relvar) for which it holds that in
all relations assigned to that variable there are no two distinct
tuples (rows) that have the same values for the attributes in this set.
Equivalently a superkey can also be defined as a set of attributes of a
relvar upon which all attributes of the relvar are functionally
dependent.

For example, the bank account number
is a super key in the bank accounts table.


Hope It Helps
aftab ahmad Profile
aftab ahmad answered
Supper key is the collection of attributes that distinguish the entity table,if one attribute can't make primary key then we make primary key with combination of different attributes.these collectively are called supper key
>>>I hope it will help you much
Aftab Ahmad
from  ISLAMABAD ,PAKISTAN

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