• Hi GilaMonster,

    Thanks for the reply 🙂

    Can u plz go thro the below paragraphs and offer me your valuable guidance/suggestions.

    When i tried to explore isolation levels i found the below stuff.

    The following statements are executed to test READCOMMITTED isolation level

    CREATE TABLE Consultants (

    ConsultantID INT IDENTITY,

    ConsultantName VARCHAR(20),

    Technology VARCHAR(15),

    HireDate DATETIME,

    HourlyRate MONEY)

    ---------------------------------------------------------------------

    -- Fill some data

    ---------------------------------------------------------------------

    INSERT INTO Consultants (ConsultantName, Technology, HireDate, HourlyRate)

    SELECT 'Jacob', 'SQL Server', '2000-10-03', 120

    INSERT INTO Consultants (ConsultantName, Technology, HireDate, HourlyRate)

    SELECT 'Smith', 'ASP.NET', '2005-01-01', 140000

    INSERT INTO Consultants (ConsultantName, Technology, HireDate, HourlyRate)

    SELECT 'Michael', 'C#.NET', '2002-10-30', 80000

    I executed the following statements in Query Window 1

    BEGIN TRAN

    UPDATE c SET

    HourlyRate = 250

    FROM Consultants c

    WHERE ConsultantName = 'Smith'

    When execcuted the following statements from Query Window 2

    select * from Consultants

    the query blocks and does not return. This query blocks with the transaction running on

    the other session. Now move back to Query Window 1 and COMMIT the transaction.

    COMMIT TRAN

    Now switch back again to Query Window 2. You will notice that the query returned the following.

    /*

    ConsultantID ConsultantName Technology HireDate HourlyRate

    ------------ -------------------- --------------- ----------------------- ---------------------

    1 Jacob SQL Server 2000-10-03 00:00:00.000 120.00

    2 Smith ASP.NET 2005-01-01 00:00:00.000 250.00

    3 Michael C#.NET 2002-10-30 00:00:00.000 100.00

    */

    I then created a clustered index on the ConsultantID column.

    ALTER TABLE Consultants

    ADD CONSTRAINT PK_Consultants PRIMARY KEY (ConsultantID)

    Now move to Query Window 1 and update the record of Smith.

    BEGIN TRAN

    UPDATE c SET

    HourlyRate = 250

    FROM Consultants c

    WHERE ConsultantName = 'Smith'

    Now, Move to Query Window 2 and run the following queries.

    SELECT *

    FROM Consultants

    WHERE ConsultantID = 3

    /*

    ConsultantID ConsultantName Technology HireDate HourlyRate

    ------------ -------------------- --------------- ----------------------- ---------------------

    3 Michael C#.NET 2002-10-30 00:00:00.000 100.00

    */

    Now, the thing i want to know is that "is still something

    there to know more about isolation levels in connection with indexes ?"

    N.B: the above code and observations were obtained from the following URL

    http://www.sqlserverandxml.com/2008/08/sql-server-transaction-isolation-level.html

    Thanks and Regards,

    Sree