TSQL Interview Questions – Part 5
Next part of TSQL Interview Questions, contd. from my previous post.
101. What are the required/mandatory parameters that have to be passed with RAISEERROR statement?
– message _id or message_str
– severity, and
102. Difference between RAISERROR and THROW
RAISERROR vs THROW: https://sqlwithmanoj.com/2012/12/20/new-throw-statement-in-sql-server-2012-vs-raiserror/
103. What severity level errors are managed in TRY-CATCH block?
A TRY…CATCH construct catches all execution errors that have a severity higher than 10 that do not close the database connection. Check about TRY-CATCH here: https://sqlwithmanoj.com/2010/06/16/try-catch-exception-handling/
104. What are row constructors?
Also known as Table Value Constructor: https://sqlwithmanoj.com/2015/02/16/sql-basics-what-are-row-constructors/.
Also check Method #5 of this post: https://sqlwithmanoj.com/2010/10/15/multiple-ways-to-insert-records-in-a-table/
105. What is SCD (Slowly Changing Dimensions)? What are its types?
Check this YouTube tutorial on SCD: v=aTnr00NnlXE
106. How many types of internal joins are there in SQL Server?
– Nested loop join
– Merge join
– Hash join
More about these: https://sqlwithmanoj.com/2010/10/06/physical-join-vs-logical-join/
107. What are pages in SQL Server? How many types of pages are there?
A page in SQL Server is an 8 KB data storage area. There are 8 types of pages, check details here: https://sqlwithmanoj.com/2011/10/12/what-are-records-pages-extents-heap/
108. How many data sources are available in SSIS?
– DataReader Source in 2005 & ADO NET Source in 2008 & above.
– Excel Source
– Flat File Source
– OLE DB Source
– Raw File Source
– Script Component
– XML Source
109. How will you deploy an SSIS package in testing, staging & production environments?
The dtutil is the command prompt utility which is used to manage SSIS packages.
This utility can copy, move, delete or verify the existence of a package.
More on: http://msdn.microsoft.com/en-us/library/ms162820.aspx
110. Where will you use Conditional Split transformation?
More info: http://msdn.microsoft.com/en-us/library/ms137886.aspx
111. What is live lock, deadlock and what is Lock escalation?
Check this YouTube tutorial on Deadlock: v=V_KLPWHfYFU
112. If you are working on a SQL database and if suddenly a developer changes the code and your queries results start giving errors, how will you check using a T-SQL query (on system tables) that what has changed in the database.
select o.name, o.object_id, o.modify_date, c.text
from sys.objects o
join sys.syscomments c
on o.object_id = c.id
113. Difference between Nested loops join, Merge join & Hash Join.
Check all differences here: https://sqlwithmanoj.com/2010/10/06/physical-join-vs-logical-join/
114. What are Surrogate Keys in a Data Warehouse?
Surrogate Keys are UNIQUE, SEQUENTIAL and MEANINGLESS generated integer numbers to identify every record in a Dimension table uniquely. The are used to JOIN Dimension tables with Fact tables.
… I’ll be adding more questions on upcoming post.