Post reply

More duration, less reads after indexing?

  • June 18, 2008 at 7:00 am

    #124376

    Hallo,

    I performed an Index Tuning Wizard on a single table, read by an external application, and applied the suggested indexes since they were the same I was going to implement on myself.

    Before indexing, i had 25K reads in 110msec; after, i have 1856 reads in 546msec.

    Which perspective should i use to analyze the fact?

    The query is a SELECT * WHERE col_1 = @par ORDER BY col_2, col_3

    The index involves those 3 columns, 2 varchar(50) and 1 int

  • June 18, 2008 at 7:15 am

    #830383

    The reads have gone down, which is good. Has the CPU time also increased, or just the duration?

    Did you run the query a couple times before taking measurements? If it was the 1st run, it could have been compliation time or time to fetch the data pages.

    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

  • June 18, 2008 at 7:34 am

    #830408

    right, i misread the values.

    CPU time decreased from an avg 375 to zero.

    Thanks!

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

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