14. Can we use Truncate command on a table which is referenced by FOREIGN KEY – No. We cannot use Truncate command on a table with Foreign Key because of referential integrity.
15. What is the use of DBCC commands – DBCC stands for database consistency checker. We use these commands to check the consistency of the databases, i.e., maintenance, validation task and status checks.
16. Can you give me some DBCC command options (Database consistency check) – DBCC CHECKDB – Ensures that tables in the db and the indexes are correctly linked.and DBCC CHECKALLOC – To check that all pages in a db are correctly allocated. DBCC SQLPERF – It gives report on current usage of transaction log in percentage. DBCC CHECKFILEGROUP – Checks all tables file group for any damage.
17. What command do we use to rename a db – sp_renamedb ‘oldname’ , ‘newname’
18. Well sometimes sp_reanmedb may not work you know because if some one is using the db it will not accept this command so what do you think you can do in such cases – In such cases we can first bring to db to single user using sp_dboptions and then we can rename that db and then we can rerun the sp_dboptions command to remove the single user mode.
19. What is the difference between a HAVING CLAUSE and a WHERE CLAUSE – Having Clause is basically used only with the GROUP BY function in a query. WHERE Clause is applied to each row before they are part of the GROUP BY function in a query.
20. What do you mean by COLLATION – Collation is basically the sort order. There are three types of sort order Dictionary case sensitive, Dictonary – case insensitive and Binary.
21. What is a Join in SQL Server – Join actually puts data from two or more tables into a single result set.
23. When do you use SQL Profiler – SQL Profiler utility allows us to basically track connections to the SQL Server and also determine activities such as which SQL Scripts are running, failed jobs etc..
24. What is a Linked Server – Linked Servers is a concept in SQL Server by which we can add other SQL Server to a Group and query both the SQL Server dbs using T-SQL Statements.
25. Can you link only other SQL Servers or any database servers such as Oracle – We can link any server provided we have the OLE-DB provider from Microsoft to allow a link. For Oracle we have a OLE-DB provider for oracle that microsoft provides to add it as a linked server to the sql server group.
26. Which stored procedure will you be running to add a linked server – sp_addlinkedserver, sp_addlinkedsrvlogin
27. What are the OS services that the SQL Server installation adds – MS SQL SERVER SERVICE, SQL AGENT SERVICE, DTC (Distribution transac co-ordinator)
28. Can you explain the role of each service – SQL SERVER – is for running the databases SQL AGENT – is for automation such as Jobs, DB Maintanance, Backups DTC – Is for linking and connecting to other SQL Servers
29. How do you troubleshoot SQL Server if its running very slow – First check the processor and memory usage to see that processor is not above 80% utilization and memory not above 40-45% utilization then check the disk utilization using Performance Monitor, Secondly, use SQL Profiler to check for the users and current SQL activities and jobs running which might be a problem. Third would be to run UPDATE_STATISTICS command to update the indexes
30. Lets say due to N/W or Security issues client is not able to connect to server or vice versa. How do you troubleshoot – First I will look