Non cluster index help required (3 questions) : SSMS 2008R2

  • Hi Friends,

    I have table

    (Table_A (A_id int(PK),

    col1 nvarchar,

    col2 nvarchar,

    col3 nvarchar,

    col4 nvarchar,

    col5 nvarcar

    Col6 nvarchar))

    A_id int(PK),--- already have one clusterd index on this column as this is PK

    I hav only ONE non clustered index on col1, col2 and col3 and i have below query

    SELECT col4, COl5, col6

    FROM Table_A a INNER JOIN Some_Table_B b

    ON a.a_id = b.b_some_id

    WHERE a. col1 = 'Some value' AND a.col2 = 'some Value' and a.col3 = 'SOme value'

    **Question 1**

    do i need more NON Clustered index on this table so that, this query will perform well(as SELECT statement has more columns which dont have any indexex, ).

    **Question 2**

    if i put the non clusterd index on the columns which are only considerd for displaying the result set

    (example, here col4, COl5, col6 with SELECT only, these columns are not utilised in WHERE or JOIN clause ) WIll this improve performance of the query

    **Question 3**

    Another question (as as i have mentined earlier NON clustred index is on col1, col2 and col3 )

    if my WHERE clause hav only col_1 and col_2 ,

    Example

    SELECT col4, COl5, col6

    FROM Table_A a INNER JOIN Some_Table_B

    ON a.a_id = b.b_some_id

    WHERE a. col1 = 'Some value' AND a.col2 = 'some Value' --- no column3 ok

    will this non cluster index help or do i need to create another index only with these two columns.

    Please do the needful.

    **Thanks in Advance

    Parixitsinh**

  • Please don't cross post. It just wastes people's time and fragments replies.

    No replies to this thread please. Direct replies to http://www.sqlservercentral.com/Forums/Topic1465465-392-1.aspx

    Gail Shaw
    Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
    SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

    We walk in the dark places no others will enter
    We stand on the bridge and no one may pass
  • Sorry Sir,

    actually i found Performence forum after posting it here.

    Thanks for your patient with me.

Viewing 3 posts - 1 through 2 (of 2 total)

You must be logged in to reply to this topic. Login to reply