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Doubt on query execution speed.

  • February 22, 2010 at 4:44 am

    #217096

    Dear Experts,

    Suppose I have a Sales_table with a column called "CountryName". I don't have any index defined on this table. (Not even clustered index). There are somany records in this table. 10% records are with "CountryName='Australia'"

    My doubt is that, Will the query

    "Select * From Sales_table" run faster than the query

    "Select * From Sales_table where CountryName='Australia'"

    ???

    Please confirm.

    Thanks in advance.

  • February 22, 2010 at 4:50 am

    #1122840

    Both will have to scan the complete table.

    The only ,noticeable, difference would be that amount of data that the non filtered version will return to the client.


    Clear Sky SQL
    My Blog[/url]

  • February 22, 2010 at 5:13 am

    #1122856

    So ultimately, execution speed will be equal for both the queries....

  • February 22, 2010 at 6:37 am

    #1122899

    I would expect the non filter to be slower , but only because of the amount of data that needs to be sent to the client. Not for any 'server' reason


    Clear Sky SQL
    My Blog[/url]

  • July 24, 2017 at 4:58 am

    This was removed by the editor as SPAM

  • July 24, 2017 at 5:19 am

    #1952330

    Please note: 7 year old thread.
    And those 'rules' are pretty useless.

    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

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