Super key:- the super key is one or more than one attribute by which we can uniquely identify an Entity
Candidate key:- if a possible subset of superkey can uniquely identify an entity uniquely and without redundant data, it`s known as a candidate key
Primary key:- uniquely identify an entity
prime attributes:- the attributes that take part in the building of a primary key are known as prime attributes
Alternate Key:- The alternate key that doesn't become the primary key
Foreign Key:- if a prime attribute in a table is a non prime attribute in another table then where it`s non prime it will be called Foreign key
Partial Key:- if an attribute can`t identify an entity uniquely but can give a bunch of related values to it then it would be called a partial key
Secondary Key:- it`s Used For indexing other than the primary key if we need to search something we search it using the Secondary key
Normalisation
No comments:
Post a Comment