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 _____is a group of single or multiple keys that identifies rows in a table.
1. Primary key
2. Candidate Key
3. Composite Key 
4. Compound Key 
5. Super Key

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Correct Answer - Option 5 : Super Key

The correct answer is Super Key.

  • There is always one primary key in a table for each record which is used to uniquely identify that record.
  • KEYS in DBMS is an attribute or set of attributes that help you to identify a row(tuple) in a relation(table). They allow you to find the relation between two tables. Keys help you uniquely identify a row in a table by a combination of one or more columns in that table. The Key is also helpful for finding a unique record or row from the table. The database key is also helpful for finding a unique record or row from the table.

 

  • There are mainly seven different types of Keys in DBMS and each key has its different functionality:

    1. Super Key -  A super key is a group of single or multiple keys that identifies rows in a table.
    2. Primary Key -  is a column or group of columns in a table that uniquely identify every row in that table.
    3. Candidate Key -  is a set of attributes that uniquely identify tuples in a table. Candidate Key is a super key with no repeated attributes.
    4. Alternate Key -  is a column or group of columns in a table that uniquely identify every row in that table.
    5. Foreign Key -  is a column that creates a relationship between two tables. The purpose of Foreign keys is to maintain data integrity and allow navigation between two different instances of an entity.
    6. Compound Key -  has two or more attributes that allow you to uniquely recognize a specific record. It is possible that each column may not be unique by itself within the database.
    7. Composite Key - A composite key is a candidate key that consists of two or more attributes (table columns) that together uniquely identify an entity occurrence (table row).
    8. Surrogate Key -  An artificial key which aims to uniquely identify each record is called a surrogate key. These kinds of keys are unique because they are created when you don't have any natural primary key.

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