MySQL Learn Simpli September 6, 2019 no Comments 1. Difference between Primary key and Unique key? Primary key allows one null value whereas unique key allows multiple null values. Primary key allows one null value whereas unique key doesn’t allow null value. Primary key doesn’t allow null value whereas unique key allows multiple null values Primary key doesn’t allow null value whereas unique key allows one null value. None 2. What does RAID stands for? Redundancy Accelerator Independent Disks Reduce Array of Independent Disks Redundant Automatic Individual Durable Redundant Array of Independent Disks None 3. What is meant by indexes? Index speed up the data retrieval Index minimize the data redundancy Index stores large number of integer values None of the above. None 4. Which of the followings are the types of locks in SQL Server? All of the above Shared locks Exclusive locks None 5. What does OLTP stands for? Ontime Transaction Program Offline Transaction Processing Online Transactional Processing Online Timebound Processing None 6. What is meant by Primary Key in SQL? Primary keys are unique names of a table. Primary keys are unique identifiers for each row in a table. Primary keys are integer ids in a table rows. primary is no of rows in table None 7. What does a trigger means in SQL? A trigger is a SQL procedure that performs some tasks on accessing db tables. A trigger is a SQL procedure that initiates an action when an event (INSERT, DELETE or UPDATE) occurs. A trigger is an event that can be raised from Stored Procedures. A trigger is a procedure which executes when an error occurred. None 8. The different types of replication available in SQL server are? Transactional Replication Merge Replication All of the above Snapshot Replication None 9. How many types of indexes are there in SQL server? none Integer and string Clustered and Non clustered Unique and non-unique None 10. Which are valid Transaction levels in SQL Server in the following answers? READ UNCOMMITTED READ COMMITTED All of the above REPEATABLE READ None Time's up
