Job Scheduling in SQL Server

Schedule Jobs:

Jobs are scheduled objects which will execute a sequence of stored statements at a particular time or at regular intervals. Considering a practical scenario like, I need to take a backup of my database at regular intervals (Daily at 12AM). How can I achieve it?

This can be achieved through jobs in sql server. I will take a very simple scenario of inserting a record in a table. This insert should happen on weekly basis (One time) with no end date. Let's see the step by step procedure to ahieve it.

Below is the table (I need to insert into this table),

Check your SQL Server agent or else start your agent (The easier way is go to your services window and search for your sql server agent and start it) . Under SQL Server Agent -> jobs -> right click and create the job. Provide the Name of your job and possible description. You can specify the owner the job too.

Next Stage:

Got to steps tab, and click New to create the steps. A job can have any number of steps. We can arrange the step. So that, it will execute on the prescribed order.

On clicking the new button in the above window, we will get the steps window. You can provide the step name and command to be executed.

After providing the command, you can check the syntax by clicking the parse button.

Go to the scheduled tab and you can schedule your job. A job may have multiple schedules.

Now, I am creating the job which recurrent/weekly once /only on sunday /Occurs at 12AM /Start date is today / No end date.

Goto the next tab "Alert" -> You can customize the message for the job failure or else you can take the existing alerts.

Go to the Notification tab -> You can specify the notification details. How you want the notification through email or through page or net send or just write it in windows app event log.

That's it. Your job is ready to go. On clicking the Jobs, you can see your new job.

Considering, I need to execute the job now. Just right click the job and click start job.

To check the activity of the job in the servers. Right click job activity monitor and check it.

In SSMS, you can check the job details in the msdb tables.

select * from sysjobs -> List down all the jobs available in the server. It holds all the information like job name/description/owner/job failure details/versionnumber/job creation date/job modification date.

select * from dbo.sysjobschedules - >This table will show the scheduled job details. Job name/next run date.

OOPS!!! That's a very lengthy article and I would like to close it. Will talk about more on Jobs in my future articles.
Venkatesan Prabu .J


Peculiar nature of identity insert in a table

Peculiar nature of identify column in sql server:
I have tried to insert some records in an identity column and got confused on the below scenario. It seems to be a bug in sql server :0 I think so,

DROP TABLE Venkattemp
-- Am creating a table
create table Venkattemp (id int identity(1,1),VAL INT)
Truncate table Venkattemp

-- Reseeding the identity column

-- Checking the current identity value on the table
select IDENT_CURRENT('Venkattemp')+1
DELETE Venkattemp WHERE ID =3
select IDENT_CURRENT('Venkattemp')+1
-- Here, why its inserting value 3 in the identity column. This is an unexpected behaviour of sql server
SELECT * FROM Venkattemp
select IDENT_CURRENT('Venkattemp')
select IDENT_CURRENT('Venkattemp')
DELETE Venkattemp WHERE ID =6
select IDENT_CURRENT('Venkattemp')
-- Here, why its not inserting 6 in the below insert statement. This is an expected behaviour of sql server
SELECT * FROM Venkattemp

Thanks and Regards,
Venkatesan Prabu .J

SQL Query challenge

Hi Readers,

Have you tried inserting a record in the table like below,

create table Venkattemp (id int identity(1,1))

Any inputs????????

Thanks and Regards,
Venkatesan Prabu .J

Search string in the stored procedure

Searching a string in the stored procedures:

Am writing after a very long break :-) I got a peculiar question in one of the forum and wish to start my article from the question started.
The query is, "Am having hard coded ip address values in the stored procedure and I need to find all the stored procedures" How to find it?

Let's see, How can we address the above said issue.
Am creating the stored procedure

SET @IP =''
All stored procedures/function details can be fetched from a system related view information_schema.routines
Let's see the same,

select * from information_schema.routines
The above query will return all the stored procedures and functions available in the database + properties and details of the objects like owner of the object, which database, when its created, whats the definition etc..,

Let move the problem, We can use the like operator to identify any hard coded IP address and it needs to be searched in the routiine definition column.

select x.ROUTINE_DEFINITION,x.specific_name,x.* from information_schema.routines x
where (x.ROUTINE_DEFINITION LIKE '%.[0-9].%' or x.ROUTINE_DEFINITION LIKE '%.[0-9][0-9].%' or x.ROUTINE_DEFINITION LIKE '%.[0-9][0-9][0-9].%')

Happy Learning!!!
Thanks and Regards,
Venkatesan Prabu .J

My T-SQL Gallery @code.msdn.microsoft

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


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

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!!!
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