Frequently Asked Questions on Alternate Key

What is basic difference between candidate key and primary key?

Both primary and the candidate key have the properties of uniquely identified elements but the main difference is that candidate keys are like candidates which are going to be selected for primary key, and each candidate key have the potential to be selected for primary key.

Can alternate key have null values?

No alternate key should not have null values, this is because in alternate key every elements should be uniquely identified and null value cannot be identified.

What is the use of alternate key in database?

Alternative key provides options for the unique identifiers which could be further used for identifying records in table, this will provide more flexibility and query optimization.

Are alternative keys must for a table?

NO, having alternative key or not is a choice depending on the table its not must, but it provides more flexibility.

Keys play an important role in organizing and accessing data in the database management system. There are many key types of keys but primary keys are mostly discussed because of their unique identification properties, we can identify the attributes of an element with the primary key, but there are also alternative keys. Which are not that extensively discussed. But are unique and present in the database table. They present as similar and alternative to the primary keys. In this article, we will understand what is primary key. Its characteristics, advantages, and examples.