Forum Replies Created

Viewing 15 posts - 7,456 through 7,470 (of 49,552 total)

  • RE: difference between estimated and actual number of rows

    It's entirely possible for the stats to be perfectly accurate and the plan terrible. As in this case, there's more to estimation than just the stats.

    Figuring out whether the plan...

    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

    October 20, 2014 at 6:59 am

    #1753478

  • RE: difference between estimated and actual number of rows

    Firstly, determine whether it's a problem that needs something to be done about.

    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

    October 20, 2014 at 6:26 am

    #1753473

  • RE: difference between estimated and actual number of rows

    Cardinality estimator assumes that, when there are multiple predicates, they are completely independent (if one affects half the table and the other affects 10% of the table then the combination...

    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

    October 20, 2014 at 5:55 am

    #1753467

  • RE: difference between estimated and actual number of rows

    Without seeing the execution plan, not really.

    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

    October 20, 2014 at 5:16 am

    #1753463

  • RE: Very Large Transaction Log File

    Shrinking the log shouldn't, by itself, cause performance problems.

    Once you've monitored for a while (few days, week), run some queries on the saved data, see what the max used space...

    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

    October 20, 2014 at 4:09 am

    #1753444

  • RE: truncate log

    Jacek Falkiewicz (10/20/2014)

    Maybe it is worthy to try opposite scenario: change to full, full backup, log backup and shrink at the end.

    Completely pointless and a waste of time.

    The reason the...

    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

    October 20, 2014 at 3:39 am

    #1753435

  • RE: truncate log

    charipg (10/20/2014)

    db is in simple recovery model, log file is around 80GB,there is not much freespace to shrink file, trying to truncate but its not release the space.

    SELECT [name],...

    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

    October 20, 2014 at 2:20 am

    #1753421

  • RE: truncate log

    Jacek Falkiewicz (10/20/2014)

    Is it simple model? Simple model is without log file.

    Nope. Simple recovery uses the log just like full/bulk logged does.

    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

    October 20, 2014 at 2:19 am

    #1753420

  • RE: Where to find debugging symbols for SQL2008R2 SP2

    I seem to recall they were never released. I know there was at least one version where the symbols weren't released, think it was R2.

    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

    October 20, 2014 at 2:18 am

    #1753418

  • RE: Why let transaction log files autogrow?

    Maddave (10/17/2014)

    Surely, all the other databases would only be affected if they had to autogrow at exactly the same time as when the disk was filled by the database with...

    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

    October 17, 2014 at 9:57 am

    #1753204

  • RE: CHECKDB reported consistency errors, but second run is clean

    Did anything happen between when you ran CheckDB and when you ran CheckTable? Anything like an index rebuild or similar?

    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

    October 17, 2014 at 9:28 am

    #1753189

  • RE: High CPU Usage for hours

    Not alone, no.

    Is this related to http://www.sqlservercentral.com/Forums/Topic1625741-2799-1.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

    October 17, 2014 at 9:00 am

    #1753177

  • RE: Why let transaction log files autogrow?

    Safety net.

    Autogrow allows for the log to not fill up if something happens to prevent log reuse. Something like an active transaction, unusually large data modification (eg archiving), failed log...

    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

    October 17, 2014 at 8:56 am

    #1753176

  • RE: CPU Utilization more than 95% for more than 3 hours

    If you're running the Profiler GUI, absolutely, and you're lucky if that's all it does.

    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

    October 17, 2014 at 7:32 am

    #1753150

  • RE: will it update view

    Views are just saved select statements. They have no data storage.

    When you query a view, all SQL does is query the tables that the view references to get the data...

    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

    October 17, 2014 at 7:24 am

    #1753146

Viewing 15 posts - 7,456 through 7,470 (of 49,552 total)