CLOUD COMPUTING
DATABASE MANAGEMENT
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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To make each record in a database unique
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To make each field in a database unique
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To make each query in a database unique
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None of the above
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Detailed explanation-1: -A primary key is critical to the operations of an RDBMS. A single table contains thousands of records, including duplicates. Therefore, it’s imperative to use a primary key or closely related foreign key to ensure no record is ever duplicated and is always uniquely identified.
Detailed explanation-2: -It uniquely identifies each row of a table. It gets a unique index for each primary key column that helps with faster access.
Detailed explanation-3: -Primary Key-a field containing a value that uniquely identifies each record in a table. The primary key is unique and prevents entering duplicate records or a null value in that field. Foreign Key-a key in a related table that refers to the primary key in another table.