What is the purpose of secondary key in database?

What is the purpose of a secondary key?

A secondary key shows the secondary value that is unique for each record. It can be used to identify the record and it is usually indexed. It is also termed as Alternate key. A table may have a primary key that is system generated and a secondary key that comes from the sources and other processes.

What is secondary key explain its purpose in relational database?

Secondary Key is the key that has not been selected to be the primary key. However, it is considered a candidate key for the primary key. Therefore, a candidate key not selected as a primary key is called secondary key. Candidate key is an attribute or set of attributes that you can consider as a Primary key.

What are secondary keys in SQL?

Alternate or Secondary keys in SQL Alternate keys are those candidate keys which are not the Primary key. There can be only one Primary key for a table. Therefore all the remaining Candidate keys are known as Alternate or Secondary keys.

What is the purpose of keys in database?

A key in DBMS is an attribute or a set of attributes that help to uniquely identify a tuple (or row) in a relation (or table). Keys are also used to establish relationships between the different tables and columns of a relational database.