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SQL SERVER INTERVIEW QUESTIONS 2014 BOOKLET -12 By Mr.J.Venkatesan Prabu - Managing Director of Kaashiv Infotech

            
      SQL SERVER INTERVIEW QUESTIONS 2014- SET 12 By 
"Mr.J.Venkatesan Prabu" 

KAASHIV INFOTECH

     [ The  Asia, India & Tamil Nadu Book Of  Record Holders ]


                                                       
    SQL Server Interview Questions 2014
SQL  SERVER –Booklet 12
-         Gives you the interview tips for SQL Server

 SQL SERVER INTERVIEW QUESTIONS WITH ANSWERS 

1. What is Cross Join?
           
            A cross join that does not have a WHERE clause produces the Cartesian product of the tables involved in the join. The size of a Cartesian product result set is the number of rows in the first table multiplied by the number of rows in the second table. The common example is when company wants to combine each product with a pricing table to analyze each product at each price.
.
2. How do SQL server 2000 and XML linked? Can XML be used to access data?

FOR XML (ROW, AUTO, EXPLICIT)
            You can execute SQL queries against existing relational databases to return results as XML rather than standard rowsets. These queries can be executed directly or from within stored procedures. To retrieve XML results, use the FOR XML clause of the SELECT statement and specify an XML mode of RAW, AUTO, or EXPLICIT.
OPENXML
            OPENXML is a Transact-SQL keyword that provides a relational/rowset view over an in-memory XML document. OPENXML is a rowset provider similar to a table or a view. OPENXML provides a way to access XML data within the Transact-SQL context by transferring data from an XML document into the relational tables. Thus, OPENXML allows you to manage an XML document and its interaction with the relational environment.
 
 3.What command do we use to rename a db? 

sp_renamedb ‘oldname’ , ‘newname’
            If someone sp_dboptions. Use sp_renamedb to rename database. Use sp_dboptions to bring database to multi user mode.

4. What are the different types of replication? Explain.

The SQL Server 2000-supported replication types are as follows:
  • Transactional
  • Snapshot
  • Merge
Snapshot replication distributes data exactly as it appears at a specific moment in time and does not monitor for updates to the data. Snapshot replication is best used as a method for replicating data those changes infrequently or where the most up-to-date values (low latency) are not a requirement. When synchronization occurs, the entire snapshot is generated and sent to Subscribers.
Transactional replication, an initial snapshot of data is applied at Subscribers, and then when data modifications are made at the Publisher, the individual transactions are captured and propagated to Subscribers.
Merge replication is the process of distributing data from Publisher to Subscribers, allowing the Publisher and Subscribers to make updates while connected or disconnected, and then merging the updates between sites when they are connected.

5. What are the OS services that the SQL Server installation adds?

MS SQL SERVER SERVICE, SQL AGENT SERVICE, DTC (Distribution transac co-ordinator)

6. What are three SQL keywords used to change or set someone’s permissions?

GRANT, DENY, and REVOKE.

7. What does it mean to have quoted identifier on? What are the implications of having it off?
            When SET QUOTED_IDENTIFIER is ON, identifiers can be delimited by double quotation marks, and literals must be delimited by single quotation marks. When SET QUOTED_IDENTIFIER is OFF, identifiers cannot be quoted and must follow all Transact-SQL rules for identifiers.

8. What is the STUFF function and how does it differ from the REPLACE function? 

            STUFF function to overwrite existing characters. Using this syntax, STUFF(string_expression, start, length, replacement_characters), string_expression is the string that will have characters substituted, start is the starting position, length is the number of characters in the string that are substituted, and replacement_characters are the new characters interjected into the string.
            REPLACE function to replace existing characters of all occurance. Using this syntax REPLACE(string_expression, search_string, replacement_string), where every incidence of search_string found in the string_expression will be replaced with replacement_string.

9. How many rows are returned by these two select statements? 

2 and 2 
Each select statement actually returns 2 rows. You can use this script to check this: 
create table mytable
( id int identity(1,1)
, mychar varchar(20)
)
go
insert mytable select null
insert mytable select ''
insert mytable select ' '
go
set ansi_nulls on
set ansi_null_dflt_on on
select * from mytable
where mychar is not null
select * from mytable
where mychar <> '' and mychar is not null
select * from mytable
where mychar <> ' ' and mychar is not null
select * from mytable where mychar = ''
select * from mytable where mychar = ' '
set ansi_null_dflt_on off
set ansi_nulls off
go
drop table mytable

10. If you run this, what does it return? 

select applock_mode('public', 'SalesApp', 'Transaction')
The type of lock being held by an application that requested it. 
This command returns the lock mode held by an application that was requested with the sp_getapplock procedure. 

insert mytable select ''
insert mytable select ' '
select * from mytable where mychar = ''
select * from mytable where mychar = ' '




KaaShiv InfoTech Offers Best Inpant Training in Chennai.



            The training at KAASHIV INFOTECH focus on developing the technical oriented concepts that turn graduates into employable assets. Handled only by professionals from MNC companies, we know how to equip you with strong technologies fundamentals.

INPLANT TRAINING SCHEDULE FOR CSE/IT/MCA STUDENTS
Day
Programme
 Day 1
BigData (Practical Demos)
Day 2
Windows 8 App Development (Practical Demos)
Day 3
Ethical Hacking (Facebook Hack,Server/Website Hacking(20 Attacks) 
Day 4
Cloud Computing (Live Server Demo,Live Pjt Implementation)
Day 5
CCNA (-Networking-Router Configurations Practical Demo)
INPLANT TRAINING SCHEDULE FOR ELECTRONIC/ELECTRICAL/EIE STUDENTS
Day
Programme
Day 1
Embedded System  (Embedded Program Designing ,Chip Burning)
Day 2
Wireless System  (Device Designing,Controlling Fans with Wireless Sensors)
Day 3
CCNA  (-Networking-Router Configurations Practical Demo)
Day 4
Ethical Hacking  (Facebook Hack,Server/Website Hacking(20 Attacks)
Day 5
Matlab  (Capture Image,Processing, Animate Images-Practical Demos)

Mechanical/Civil Inplant training Schedule

Day
Programme
Day 1
Aircraft Designing
Day 2
Vehicle Movement in Airports
Day 3
3D Packaging Designs
Day 4
3D Modeling
Day 5
3D Window Shading


Address:

KAASHIV INFO TECH
Shivanantha Building,
X41, 5th Floor,2nd Avenue,
(Near Ayyappan Temple)
Anna Nagar, Chennai = 600040.
Send Us Your Request Email To  arun@kaashivinfotech.com,
                                                      kaashiv.info@gmail.com ,
                                                            venkat@kaashivinfotech.com
Contact Number : 9840678906 ,9003718877 , 9962345637 .



Visit our other websites

http://www.inplanttrainingchennai.com
http://www.inplanttraining-in-chennai.com
http://www.Kaashiveinotech.com
http://www.internshipinchennai.in

https://plus.google.com/u/0/b/110228862465265998202/dashboard/overview

https://plus.google.com/u/0/b/117408505876070870512/dashboard/overview

https://plus.google.com/u/0/b/104468163439231303834/dashboard/overview

https://plus.google.com/u/0/b/117640664472494971423/dashboard/overview

Feedback URLS

KaaShiv InfoTech Facebook Page
https://www.facebook.com/KaaShivInfoTech

Inplant Training Program in Chennai
https://www.facebook.com/pages/Inplant-Training-Program-in-Chennai/1402097696706380

Internship Training Program in Chennai
https://www.facebook.com/pages/Internship-in-Chennai-KaaShiv/1446147235603704

 Facebook Inplant Training page

SQL SERVER INTERVIEW QUESTIONS 2014 BOOKLET -11 By Mr.J.Venkatesan Prabu - Managing Director of Kaashiv Infotech

            
      SQL SERVER INTERVIEW QUESTIONS 2014- SET 11 By 
"Mr.J.Venkatesan Prabu" 

KAASHIV INFOTECH

     [ The  Asia, India & Tamil Nadu Book Of  Record Holders ]


                                                       
    SQL Server Interview Questions 2014
SQL  SERVER –Booklet 11
-         Gives you the interview tips for SQL Server

 SQL SERVER INTERVIEW QUESTIONS WITH ANSWERS 

1. Why we cannot use column alias in where clause but we can use it in order by clause of select statement in sql server?

For example, it is incorrect to write:
SELECT Roll_No AS Id From Student WHERE Id > 1

While it correct:
SELECT Roll_No AS Id From Student ORDER BY Id
In sql server order of execution of different clauses of a select statement is following order:
Clause of select statement
Execution order
FROM
1
ON
2
JOIN
3
WHERE
4
GROUP BY
5
WITH CUBE or WITH ROLLUP
6
HAVING
7
SELECT
8
DISTINCT
9
ORDER BY
10
TOP
11

It is clear the WHERE clause executes before the SELECT clause so WHERE clause has no knowledge about column alias of SELECT clause while ORDER BY clause executes after the SELECT clause so it know about column alias of SELECT clause.



2.Which command using Query Analyzer will give you the version of SQL server and operating system?

SELECT SERVERPROPERTY ('productversion'), SERVERPROPERTY ('productlevel'), SERVERPROPERTY ('edition').

3. What is SQL Server Agent?
SQL Server agent plays an important role in the day-to-day tasks of a database administrator (DBA). It is often overlooked as one of the main tools for SQL Server management. Its purpose is to ease the implementation of tasks for the DBA, with its full- function scheduling engine, which allows you to schedule your own jobs and scripts.

4. Can a stored procedure call itself or recursive stored procedure? How much level SP nesting is possible?
Yes. Because Transact-SQL supports recursion, you can write stored procedures that call themselves. Recursion can be defined as a method of problem solving wherein the solution is arrived at by repetitively applying it to subsets of the problem. A common application of recursive logic is to perform numeric computations that lend themselves to repetitive evaluation by the same processing steps. Stored procedures are nested when one stored procedure calls another or executes managed code by referencing a CLR routine, type, or aggregate. You can nest stored procedures and managed code references up to 32 levels.

5. What is Log Shipping?

Log shipping is the process of automating the backup of database and transaction log files on a production SQL server, and then restoring them onto a standby server. Enterprise Editions only supports log shipping. In log shipping the transactional log file from one server is automatically updated into the backup database on the other server. If one server fails, the other server will have the same db and can be used this as the Disaster Recovery plan. The key feature of log shipping is that it will automatically backup transaction logs throughout the day and automatically restore them on the standby server at defined interval.

6. Name 3 ways to get an accurate count of the number of records in a table?

SELECT * FROM table1 
SELECT COUNT(*) FROM table1 
SELECT rows FROM sysindexes WHERE id = OBJECT_ID(table1) AND indid < 2

7. What does it mean to have QUOTED_IDENTIFIER ON? What are the implications of having it OFF?

When SET QUOTED_IDENTIFIER is ON, identifiers can be delimited by double quotation marks, and literals must be delimited by single quotation marks. When SET QUOTED_IDENTIFIER is OFF, identifiers cannot be quoted and must follow all Transact-SQL rules for identifiers.

8.What is NOT NULL Constraint?

A NOT NULL constraint enforces that the column will not accept null values. The not null constraints are used to enforce domain integrity, as the check constraints.

9. How to get @@ERROR and @@ROWCOUNT at the same time?

If @@Rowcount is checked after Error checking statement then it will have 0 as the value of @@Recordcount as it would have been reset. And if @@Recordcount is checked before the error-checking statement then @@Error would get reset. To get @@error and @@rowcount at the same time do both in same statement and store them in local variable.
SELECT @RC = @@ROWCOUNT, @ER = @@ERROR

10. What is a Scheduled Jobs or What is a Scheduled Tasks?
Scheduled tasks let user automate processes that run on regular or predictable cycles. User can schedule administrative tasks, such as cube processing, to run during times of slow business activity. User can also determine the order in which tasks run by creating job steps within a SQL Server Agent job. E.g. back up database, Update Stats of Tables. Job steps give user control over flow of execution. If one job fails, user can configure SQL Server Agent to continue to run the remaining tasks or to stop execution.

11. What are the advantages of using Stored Procedures?
  1. Stored procedure can reduced network traffic and latency, boosting application performance.
  2. Stored procedure execution plans can be reused, staying cached in SQL Server's memory, reducing server overhead.
  3. Stored procedures help promote code reuse.
  4. Stored procedures can encapsulate logic. You can change stored procedure code without affecting clients.
  5. Stored procedures provide better security to your data.
12. What is a table called, if it has neither Cluster nor Non-cluster Index? What is it used for?
Unindexed table or Heap. Microsoft Press Books and Book on Line (BOL) refers it as Heap. A heap is a table that does not have a clustered index and, therefore, the pages are not linked by pointers. The IAM pages are the only structures that link the pages in a table together. Unindexed tables are good for fast storing of data. Many times it is better to drop all indexes from table and then do bulk of inserts and to restore those indexes after that.

13. Can SQL Servers linked to other servers like Oracle?
SQL Server can be linked to any server provided it has OLE-DB provider from Microsoft to allow a link. E.g. Oracle has an OLE-DB provider for oracle that Microsoft provides to add it as linked server to SQL Server group.

14. How do you load large data to the SQL server database?
            BulkCopy is a tool used to copy huge amount of data from tables. BULK INSERT command helps to Imports a data file into a database table or view in a user-specified format.

15. What is Self Join?

            This is a particular case when one table joins to itself, with one or two aliases to avoid confusion. A self join can be of any type, as long as the joined tables are the same. A self join is rather unique in that it involves a relationship with only one table. The common example is when company has a hierarchal reporting structure whereby one member of staff reports to another.

KaaShiv InfoTech Offers Best Inpant Training in Chennai.


            The training at KAASHIV INFOTECH focus on developing the technical oriented concepts that turn graduates into employable assets. Handled only by professionals from MNC companies, we know how to equip you with strong technologies fundamentals.

INPLANT TRAINING SCHEDULE FOR CSE/IT/MCA STUDENTS
Day
Programme
 Day 1
BigData (Practical Demos)
Day 2
Windows 8 App Development (Practical Demos)
Day 3
Ethical Hacking (Facebook Hack,Server/Website Hacking(20 Attacks) 
Day 4
Cloud Computing (Live Server Demo,Live Pjt Implementation)
Day 5
CCNA (-Networking-Router Configurations Practical Demo)
INPLANT TRAINING SCHEDULE FOR ELECTRONIC/ELECTRICAL/EIE STUDENTS
Day
Programme
Day 1
Embedded System  (Embedded Program Designing ,Chip Burning)
Day 2
Wireless System  (Device Designing,Controlling Fans with Wireless Sensors)
Day 3
CCNA  (-Networking-Router Configurations Practical Demo)
Day 4
Ethical Hacking  (Facebook Hack,Server/Website Hacking(20 Attacks)
Day 5
Matlab  (Capture Image,Processing, Animate Images-Practical Demos)

Mechanical/Civil Inplant training Schedule

Day
Programme
Day 1
Aircraft Designing
Day 2
Vehicle Movement in Airports
Day 3
3D Packaging Designs
Day 4
3D Modeling
Day 5
3D Window Shading


Address:

KAASHIV INFO TECH
Shivanantha Building,
X41, 5th Floor,2nd Avenue,
(Near Ayyappan Temple)
Anna Nagar, Chennai = 600040.
Send Us Your Request Email To  arun@kaashivinfotech.com,
                                                      kaashiv.info@gmail.com ,
                                                            venkat@kaashivinfotech.com
Contact Number : 9840678906 ,9003718877 , 9962345637 .



Visit our other websites

http://www.inplanttrainingchennai.com
http://www.inplanttraining-in-chennai.com
http://www.Kaashiveinotech.com
http://www.internshipinchennai.in

https://plus.google.com/u/0/b/110228862465265998202/dashboard/overview

https://plus.google.com/u/0/b/117408505876070870512/dashboard/overview

https://plus.google.com/u/0/b/104468163439231303834/dashboard/overview

https://plus.google.com/u/0/b/117640664472494971423/dashboard/overview

Feedback URLS

KaaShiv InfoTech Facebook Page
https://www.facebook.com/KaaShivInfoTech

Inplant Training Program in Chennai
https://www.facebook.com/pages/Inplant-Training-Program-in-Chennai/1402097696706380

Internship Training Program in Chennai
https://www.facebook.com/pages/Internship-in-Chennai-KaaShiv/1446147235603704

 Facebook Inplant Training page

My T-SQL Gallery @code.msdn.microsoft


Created my own T-SQL Gallery in Microsoft site. Do visit the same and share your feedback,

http://code.msdn.microsoft.com/VenkatSQLSample/Thread/List.aspx

Thanks and Regards,
Venkatesan Prabu .J

SQL Server Interview questions - Part 1

What is the significance of NULL value and why should we avoid permitting null values?
Null means no entry has been made. It implies that the value is either unknown or undefined.We should avoid permitting null values because Column with NULL values can't have PRIMARY KEY constraints. Certain calculations can be inaccurate if NULL columns are involved.

What is SQL whats its uses and its component ?
The Structured Query Language (SQL) is foundation for all relational database systems. Most of the large-scale databases use the SQL to define all user and administrator interactions. It enable us to retrieve the data from based on our exact requirement. We will be given a flexibility to store the data in our own format.


The DML component of SQL comprises four basic statements:
* SELECT to get rows from tables
* UPDATE to update the rows of tables
* DELETE to remove rows from tables
* INSERT to add new rows to tables


What is DTS in SQL Server ?
Data Transformation Services is used to transfer the data from one source to our required destination. Considering am having some data in sql server and I need to transfer the data to Excel destination. Its highly possible with dialogue based tool called Data Transformation services. More customization can be achieved using SSIS. A specialized tool used to do such migration works.


What is the difference between SQL and Pl/Sql ?

Straight forward. SQL is a single statement to finish up our work.Considering, I need some data from a particular table. “Select * from table” will fetch the necessary information. Where as I need to do some row by row processing. In that case, we need to go for Procedural Logic / SQL.

What is the significance of NULL value and why should we avoid permitting null values?
Null means no entry has been made. It implies that the value is either unknown or undefined.We should avoid permitting null values because Column with NULL values can't have PRIMARY KEY constraints. Certain calculations can be inaccurate if NULL columns are involved.

Difference between primary key and Unique key?
Both constraints will share a common property called uniqueness. The data in the column should be unique. The basic difference is,
· Primary key won’t allow null value. Whereas, unique key will accept null value but only one null value.
· On creating primary key, it will automatically format the data inturn creates clustered index on the table. Whereas, this characteristics is not associated with unique key.
· Only one primary key can be created for the table. Any number of Unique key can be created for the table.

Select Statement in SQL Server

Select Statement in SQL Server

String Functions in sql server

String Functions in sql server
Substring/Len/replace/Ltrim/Rtrim

SQL Server Interview Question - Part 2

What is normalization?

Normalization is the basic concept used in designing a database. Its nothing but, an advise given to the database to have minimal repetition of data, highly structured, highly secured, easy to retrieve. In high level definition, the Process of organizing data into tables is referred to as normalization.


What is a stored procedure:
Stored procedures are precompiled T-SQL statements combined to perform a single task of several tasks. Its basically like a Macro so when you invoke the Stored procedure, you actually run a set of statements. As, its precompiled statement, execution of Stored procedure is compatatively high when compared to an ordinary T-SQL statement.


What is the difference between UNION ALL Statement and UNION ?
The main difference between UNION ALL statement and UNION is UNION All statement is much faster than UNION,the reason behind this is that because UNION ALL statement does not look for duplicate rows, but on the other hand UNION statement does look for duplicate rows, whether or not they exist.

Example for Stored Procedure?
They are three kinds of stored procedures,1.System stored procedure – Start with sp_2. User defined stored procedure – SP created by the user.3. Extended stored procedure – SP used to invoke a process in the external systems.Example for system stored proceduresp_helpdb - Database and its propertiessp_who2 – Gives details about the current user connected to your system. sp_renamedb – Enable you to rename your database


What is a trigger?

Triggers are precompiled statements similar to Stored Procedure. It will automatically invoke for a particular operation. Triggers are basically used to implement business rules.


What is a view?
If we have several tables in a db and we want to view only specific columns from specific tables we can go for views. It would also suffice the needs of security some times allowing specfic users to see only specific columns based on the permission that we can configure on the view. Views also reduce the effort that is required for writing queries to access specific columns every time.


What is an Index?
When queries are run against a db, an index on that db basically helps in the way the data is sorted to process the query for faster and data retrievals are much faster when we have an index.


What are the types of indexes available with SQL Server?

There are basically two types of indexes that we use with the SQL ServerClustered -

1. It will format the entire table, inturn physically sort the table.

2. Only one clustered index can be created for a table.

3. Data will be located in the leaf level.

4. By default, primary key will create clustered index on the table.

Non-Clustered Index

1. It wont touch the structure of the table.

2. It forms an index table as reference to the exact data.

3. A reference to the data will be located in the leaf level.

4. For a table, we can create 249 non clustered index.

Happy Learning!!!
Regards,
Venkatesan Prabu .J

SQL Interview question

Extent Vs Page?

Pages are low level unit to store the exact data in sql server. Basically, the data will be stored in the mdf, ldf, ndf files. Inturn, pages are logical units available in sql server.The size of the page is 8KB.

Eight consecutive pages will form an extent 8 * 8KB = 64KB.

Thus I/O level operation will be happening at pages level.The pages will hold a template information at the start of each page (header of the page).

They are,

1. page number,

2. page type,

3. the amount of free space on the page,

4. the allocation unit ID of the object that owns the page.

Extents will be classifed into two types,

1. Uniform extents

2. Mixed extents

Uniform Extents:It occupied or used by a single object. Inturn, a single object will hold the entire 8 pages.Mixed

Extents:Mulitple objects will use the same extent. SQL Server will allow a max of eight objects to use a shared extent.

Property of SQL Server :Initally if an object is created, sql server will allocate the object to the mixed extent and once if the size reaches 8 pages and more... immediately, a new uniform extent will be provided for that particular object.

Herecomes, our fragmentation and reindexing concepts.

Best Joke - Enjoy it

Best Joke - Enjoy it