Browse by Tags

CSS SQL Server Engineers

This is the official team Web Log for Microsoft Customer Service and Support (CSS) SQL Support. Posts are provided by the CSS SQL Escalation Services
  • Blog Post: How It Works: FileStream (RsFx) Garbage Collection–Part (2)

    In a previous post I outlined the basics of File Stream, garbage collection: http://blogs.msdn.com/b/psssql/archive/2011/06/23/how-it-works-filestream-rsfx-garbage-collection.aspx This post continues the discussion, outlining specific details as to how the garbage collection progresses. A Single GC Thread...
  • Blog Post: As The World Turns: SQL Server NUMA Memory Node and the Operating System Proximity

    It felt a bit like ‘As The World Turns’ as I unraveled how the following worked so the title is a bit of a tribute to my grandmother.  She could not miss here ‘stories’ in the afternoon. Proximity Before I dive into the details I would like to talk about NUMA node proximity.    The...
  • Blog Post: Spatial Index is NOT used when SUBQUERY used

    I have found the following link to be invaluable when working with and tuning SQL Server Spatial indexes:  http://technet.microsoft.com/en-us/library/bb895265.aspx However, the link is not as clear as it could be about the Spatial index selections made by the SQL Server query processing.  Here...
  • Blog Post: All about RollbackSnapshotTempDB...

    I’ve been recently involved in several cases where Databases named RollbackSnapshotTempDB +<someGUID> were generating confusion. The purpose of this post is to clarify their origin and use and to enable SQL Server admins to know what to do if they need to deal with them. The following topics...
  • Blog Post: Every time I ‘ATTACH DATABASE’ SQL logs error 1314 for SetFileIoOverlappedRange

    Turns out this is an issue in the SQL Server code and the error is a bit noisy during attach database. When opening the database files, SQL Server calls SetFileIoOverlappedRange (when enabled properly) in order to help improve I/O performance.  This is commonly done under the SQL Server, service...
  • Blog Post: How It Works: SQL Server 2012 Database Engine Task Scheduling

    Over the years the SQL Server scheduling algorithms have been documented in various publications.  Specifically, ‘ The Guru’s Guide to SQL Server Architecture and Internals’ has a chapter, written by the scheduler developer (Sameer) and Ken; and I reviewed the technical content, covering the details...
  • Blog Post: When Does sp_prepare Return Metadata

    I was running an RML Utilities Suite test pass and encountered varying behavior from our sp_prepare suite.  Here is what I uncovered. The command sp_prepare returns (or does not return) metadata depending on the server version.  For the client version, it is only significant whether it is prior...
  • Blog Post: SQLCLR and sp_OA* procedures are not compatible

    We ran into an issue today that is a bug you may need to be aware of because of its behavior.   When a SQLCLR procedure calls back into the SQL Server (in proc provider) and executes sp_OA*, during the callback activity, it triggers a bug (currently filed and being evaluated) that results in...
  • Blog Post: How It Works: SQL Server 32 bit PAE/AWE on (SQL 2005, 2008, and 2008 R2) – Not Using As Much RAM As Expected!

    This issue was puzzling until we stepped through the code and studied it in some detail.   The report was “SQL Server won’t use the physical memory I expect it to use.” Scenario:   SQL Server 2008 R2, 32GB RAM  - SQL only using ~22GB of total memory and won’t use anymore. Let me try...
  • Blog Post: FileNotFoundException with Microsoft.AnalysisServices.Xmla

    I ran across two cases that were hitting the following Exception within SharePoint trying to run the PowerPivot Management Portal.  This was located in the SharePoint ULS Log: EXCEPTION: System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.AnalysisServices.Xmla, Version=11...
  • Blog Post: How Can Reference Counting Be A Leading Memory Scribbler Cause?

    The concept of the memory scribbler comes up quite a bit in support.   The term can often be over used but I ran into a specific example that commonly fools people, including support engineers.  The random nature and even the resulting behaviors are so broad that these issues often take...
  • Blog Post: T-SQL Update Takes Much Longer Than The Matching Select Statement

    I realize the title is generic and that is because the problem is generic.   On the surface it would not surprise me that an update takes longer than a select. (A little bit anyway.) There is logging, updates to index rows, triggers, replication needs, AlwaysOn needs, perhaps page splits and...
  • Blog Post: SQL Server: Correlating Timestamps From Various Data Points

    I was looking at data from a customer, in a different time zone (UTC+1) from mine, this week involving SQL Server AlwaysOn (HADRON) and found that lining up the timestamps in the various logs was challenging.   Some times are local to the SQL Server instance, others UTC and yet other utilities...
  • Blog Post: How It Works: Online Index Rebuild - Can Cause Increased Fragmentation

    SQL Server Books Online alludes to the fragmentation possibility but does not fully explain that the Online Index rebuilding may increase fragmentation when it is allowed to run with MAX DOP > 1 and ALLOW_PAGE_LOCKS = OFF directives . The process of building an online index involves maintaining the...
  • Blog Post: PowerPivot : When versions get mixed up…

    I worked a case today where they were trying to get SQL 2012 Reporting Services installed in a SharePoint environment that also had SQL 2008 R2 PowerPivot installed.  This, by itself, is fine and wasn’t really causing the problem.  When they tried to open the Excel Workbook from SharePoint...
  • Blog Post: How It Works: When is the FlushCache message added to SQL Server Error Log?

    FlushCache is the SQL Server routine that performs the checkpoint operation.  The following message is output to the SQL Server error log when trace flag ( 3504 ) is enabled. 2012-05-30 02:01:56.31 spid14s     FlushCache: cleaned up 216539 bufs with 154471 writes in 69071 ms...
  • Blog Post: SetFileIoOverlappedRange Can Lead to Unexpected Behavior for SQL Server 2008 R2 or SQL Server 2012 (Denali)

    You should be aware the Windows bug with API = SetFileIoOverlappedRange .   This is used by SQL Server (2008 R2 and SQL 2012) only when Locked Pages has been enabled and is in use by the SQL Server. SQL Server Support has NOT encountered this in a production environment.  The issue was found...
  • Blog Post: The case of the incorrect page numbers

    As you may or may not know, SSRS 2008 R2 added the ability to automatically create page breaks on group changes.  Historically, people attempted to use custom code to accomplish this and, while it worked, the pagination logic we use in SSRS 2008 R2 breaks the standard implementation of this for...
  • Blog Post: How It Works: sys.dm_tran_session_transactions

    For some reason I have been looking at DMV output closely the last couple of weeks.    I just blogged about the pending I/O requests and now I have a behavior to outline for dm_tran_session_transactions for todays blog. select * from sys . dm_tran_session_transactions The scenario I was...
  • Blog Post: SQL Server 2008 R2 does not start when applying certain hotfix updates

    We have noticed that when you install certain hotfixes (this includes Cumulative Update 1 and certain versions of security update MS11-049 etc. ) on an SQL Server 2008 R2 RTM Instance on which Utility Control Point is configured, the installer fails to apply the upgrade scripts and SQL Server does not...
Page 1 of 1 (20 items)