Post reply

Transaction log

  • November 22, 2011 at 1:00 am

    #248319

    Hi all,

    Anyone have a great link to describe the managing of transaction logs?

    I am busy reading up, and there's a few sites that says a lot of stuff differently, so I thought let me ask the SQL guys I trust most.

    Thanks in advance,

    Ruan

  • November 22, 2011 at 1:49 am

    #1411255

    Managing Transaction Logs[/url]

    The article's old and an updated version will be published soon. If you have any questions after reading that, please ask.

    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 22, 2011 at 1:54 am

    #1411260

    Thanks!

    I have one question, may be a simple question but wondering if it is possible.

    I know that it is possible to create an additional ldf. But is it possible to configure the ldf's to do different jobs?

    Let's say one ldf specifically for queries etc. and one for mirroring? If I have one ldf then EVERYTHING is written to this ldf.

    Now if this is possible (not sure if it is) but will it reduce workload and improve performance?

    Regards

  • November 22, 2011 at 1:55 am

    #1411263

    Apologies for asking this before reading the post, but for some reason I was thinking of this possibility the whole morning 🙂

  • November 22, 2011 at 2:08 am

    #1411267

    Okay, never mind, that was a stupid question 😛

  • November 22, 2011 at 2:23 am

    #1411271

    RuanK (11/22/2011)

    But is it possible to configure the ldf's to do different jobs?

    No, and I get the impression from that question you don't understand how the log is used. It's not that the log records written by data modifications are only used for data modifications and the mirroring uses something else.

    The mirroring (and CDC, replication, crash recovery, etc) all have to read the log records that the data modifications wrote. So if an update is run, that update is logged (before and after). Mirroring then has to read those log records so that they an be transferred to the mirror server. Replication would have to read those log records to see if they need to be replicated. Log backups would need to read those log records in order to write them to a backup file, etc, etc.

    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 22, 2011 at 2:24 am

    #1411272

    Might also be worth while reading this, it explains a bit more about the details of how SQL uses the log - http://qa.sqlservercentral.com/articles/Transaction+Log/72488/

    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 22, 2011 at 2:25 am

    #1411273

    Thanks, I knew that question was a bit too far fetched

Viewing 8 posts - 1 through 7 (of 7 total)

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