Forum Replies Created

Viewing 15 posts - 22,531 through 22,545 (of 49,552 total)

  • RE: SQL Agent Job running a CheckDB, completion times all over the place...?

    anthony.green (11/3/2011)

    I do a checkdb once a month using

    Is once a month often enough? Do you retain all your backups (logs included) for a full month?

    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

    November 3, 2011 at 10:17 am

    #1402756

  • RE: SQL Agent Job running a CheckDB, completion times all over the place...?

    IO contention? CheckDB is IO intensive, if something else is hammering the IO subsystem at the time it could cause this.

    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

    November 3, 2011 at 10:15 am

    #1402752

  • RE: When is a scan cheaper than a seek?

    The Dixie Flatline (11/3/2011)

    Gail and Lynn, it is also worth noting the the scan is feeding directly into a merge join, so no intermediate sorting or hashing is required for...

    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

    November 3, 2011 at 10:11 am

    #1402748

  • RE: How to troubleshoot really high memory waits?

    Ok, but that doesn't tell us anything useful. You're going to have to dig in further if you want to investigate this.

    sys.dm_os_waiting_tasks, sys.dm_os_wait_stats are the two DMVs to start 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

    November 3, 2011 at 9:44 am

    #1402728

  • RE: Proper Domain Accounts Needed for a "Proper" Install Of SQL Server

    http://msdn.microsoft.com/en-us/library/ms143504.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

    November 3, 2011 at 9:33 am

    #1402721

  • RE: How to troubleshoot really high memory waits?

    What's the wait type? What's the wait resource?

    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

    November 3, 2011 at 9:30 am

    #1402717

  • RE: When is a scan cheaper than a seek?

    Artoo22 (11/3/2011)

    Before running each one I issued DBCC FREEPROCCACHE & DBCC DROPCLEANBUFFERS.

    I ran each one twice in succession.

    I was generating the execution plan.

    I have run the same test with execution...

    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

    November 3, 2011 at 9:26 am

    #1402711

  • RE: When is a scan cheaper than a seek?

    Omar Ismail (11/3/2011)

    Therefore, my answer to you is NEVER, especially in today’s production environment, where SMALL is not in the dictionary.

    Unfortunately this is wrong. I can easily conjure an example...

    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

    November 3, 2011 at 9:23 am

    #1402710

  • RE: TEMPDB on instances in a cluster question

    The recommendation is per-instance. The fact that there are multiple instances on the server don't make the slightest difference to the number of files a tempDB should have.

    If all...

    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

    November 3, 2011 at 7:50 am

    #1402647

  • RE: Hardware Config Vs SQL Server performance

    Absolutely. These days anyone running 32 bit SQL or OS needs a really good reason why. Even desktops are going full 64-bit (I've been running only 64-bit OS on my...

    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

    November 3, 2011 at 7:32 am

    #1402631

  • RE: When is a scan cheaper than a seek?

    dva2007 (11/3/2011)

    I always thought if it is big table then index seek would be faster. it is clear that for smaller table it is possible that even table scan is...

    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

    November 3, 2011 at 7:20 am

    #1402627

  • RE: TEMPDB on instances in a cluster question

    jspatz (11/3/2011)

    Best practice states you should add as many data files to your tempdb as their are cores in the server...

    Nope

    http://sqlskills.com/BLOGS/PAUL/post/A-SQL-Server-DBA-myth-a-day-(1230)-tempdb-should-always-have-one-data-file-per-processor-core.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

    November 3, 2011 at 7:16 am

    #1402618

  • RE: When is a scan cheaper than a seek?

    Not offhand.

    Second execution (so not incurring data caching), execution plan off when you pulled those IO and time stats?

    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

    November 3, 2011 at 7:02 am

    #1402613

  • RE: SQL Server Query Writing Help Needed

    ankita.patel01 81294 (11/3/2011)

    This is not bringing back expected result or the expected row count back.

    That's not going to help anyone fix the code...

    What's it doing wrong? What should the queries...

    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

    November 3, 2011 at 6:57 am

    #1402608

  • RE: When is a scan cheaper than a seek?

    120 000 reads for the seek vs 20 000 for the scan. Pretty clear why SQL chooses a scan here.

    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

    November 3, 2011 at 6:55 am

    #1402607

Viewing 15 posts - 22,531 through 22,545 (of 49,552 total)