1. What does RDBMS stand for?
Explanation: RDBMS stands for Relational Database Management System, which is a database management system based on the relational model.
Report for correction2. In an RDBMS, what is a primary key?
Explanation: A primary key is a column or set of columns in a table that uniquely identifies each record in that table.
Report for correction3. Which SQL command is used to retrieve data from a database in an RDBMS?
Explanation: The SELECT statement in SQL is used to retrieve data from a database.
Report for correction4. What is the purpose of the WHERE clause in an SQL query?
Explanation: The WHERE clause is used to filter rows in an SQL query based on a specified condition.
Report for correction5. In an RDBMS, what is a foreign key?
Explanation: A foreign key is a column in a table that references the primary key in another table, establishing a relationship between the tables.
Report for correction6. What is normalization in the context of RDBMS?
Explanation: Normalization is the process of organizing data into tables and reducing data redundancy to improve data integrity and efficiency.
Report for correction7. Which type of join returns all rows from both tables, joining them where there is a match?
Explanation: A FULL JOIN returns all rows from both tables and joins them where there is a match, including unmatched rows from both tables.
Report for correction8. What is the purpose of the GROUP BY clause in SQL?
Explanation: The GROUP BY clause is used to group rows with the same values in specified columns, often used with aggregate functions like SUM or COUNT.
Report for correction9. Which SQL command is used to add new data to a table in an RDBMS?
Explanation: The INSERT statement in SQL is used to add new data (rows) to a table.
Report for correction10. What is the purpose of the ORDER BY clause in SQL?
Explanation: The ORDER BY clause is used to specify the order in which the result set should be returned, either in ascending (ASC) , or descending (DESC) order.
Report for correction11. Which type of index stores a separate data structure to optimize query performance in an RDBMS?
Explanation: A non-clustered index in an RDBMS stores a separate data structure to optimize query performance, whereas a clustered index determines the physical order of the data rows.
Report for correction12. What is the purpose of the COMMIT statement in SQL?
Explanation: The COMMIT statement in SQL is used to save (commit) changes made to the database since the last COMMIT or ROLLBACK statement.
Report for correction13. In an RDBMS, what is the ACID property?
Explanation: The ACID properties (Atomicity, Consistency, Isolation, Durability) ensure the reliability of database transactions in an RDBMS.
Report for correction14. Which SQL statement is used to modify existing data in a table?
Explanation: The UPDATE statement in SQL is used to modify existing data (rows) in a table.
Report for correction15. What is the purpose of the JOIN clause in SQL?
Explanation: The JOIN clause in SQL is used to combine rows from two or more tables based on a related column between them.
Report for correction16. In the context of RDBMS, what is a view?
Explanation: In an RDBMS, a view is a virtual table that is based on the result of a SELECT query and does not store data itself.
Report for correction17. What is a stored procedure in an RDBMS?
Explanation: A stored procedure in an RDBMS is a precompiled and stored set of SQL statements that can be executed as a single unit.
Report for correction18. In SQL, what is the purpose of the HAVING clause?
Explanation: The HAVING clause in SQL is used to filter grouped rows based on a condition, typically used with the GROUP BY clause.
Report for correction19. In SQL, which aggregate function returns the number of rows in a result set?
Explanation: The COUNT aggregate function in SQL returns the number of rows in a result set.
Report for correction20. What is the purpose of the ROLLBACK statement in SQL?
Explanation: The ROLLBACK statement in SQL is used to undo changes made since the last COMMIT statement, ensuring data consistency.
Report for correction21. Which SQL command is used to delete data from a table in an RDBMS?
Explanation: The DELETE statement in SQL is used to remove data (rows) from a table in an RDBMS.
Report for correction22. What is referential integrity in the context of RDBMS?
Explanation: Referential integrity in an RDBMS ensures that foreign key values in one table match the corresponding primary key values in another table, maintaining data consistency.
Report for correction23. What is the purpose of the UNION operator in SQL?
Explanation: The UNION operator in SQL is used to combine rows from two or more tables into a single result set.
Report for correction24. What is the role of the DBMS in an RDBMS?
Explanation: The Database Management System (DBMS) in an RDBMS is responsible for managing the physical storage of data, among other tasks.
Report for correction25. Which of the following is NOT a valid data type in SQL?
Explanation: BOOLEAN is not a standard SQL data type. SQL databases typically use different data types to represent boolean values, such as BIT or BOOLEAN.
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