SQL Server Interview Question and Answers

6. What are the difference between clustered and a non-clustered index?
  A Clustered index is a special type of index that reorders the way in which each records in the table are physically stored.
A Non clustered index is a special type of index in which the logical order of the index does not match the physical stored order of the rows on disk.
7. What are the System Database in Sql server 2008?
  • Master
  • Model
  • Msdb
  • Tempdb
  • Resource
8. What are the different locks in Sql Server?
  • Intent
  • Shared
  • Update
  • Exclusive
  • Schema
  • Bulk Update
9. What are the different types of Sub-Queries?
  • Single row subquery
  • Multiple row subquery
  • Correralted row subquery
10. What are constraints? Explain different types of constraints?
    Constraints is a rule or restriction concerning a piece of data that is enforced at the data level. A Constraint clause can constrain a single column or group of columns in a table.
    There are five types of Constraint namely

  • Null / Not Null
  • Primary Key
  • Unique
  • Check or Validation
  • Foreign Key or References Key


Page 2 of 15