Deadlock Monitor Also Grants Locks

  One of the best parts of my job is that I get to learn something new each and everyday.  This week I learned something completely new about deadlock monitor.  Deadlock monitor grants locks, yes you read that correctly. In a very small window the lock monitor prevents the releasing lock owner from directly granting…

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SQL Server and SSDs – RDORR’s Learning Notes – Part 1

I am very hesitant to post anything that I don’t have the full details on.  However, with SSD deployments moving so rapidly I thought it might be helpful to share some of my learning’s to date. I make no claims of being an expert in this area.   However, I have been doing research that I…

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Capping CPU using Resource Governor – The Concurrency Mathematics

Here is what you need to know: A = πr2 Okay, not really as that is the formula for the area of a circle but it does set the stage for this discussion.   I have been working with the CAP_CPU_PERCENT (RESOURCE POOL) setting as it relates to concurrency.   This turned into a mathematical exercise I…

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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 idea…

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Spatial Indexing: From 4 Days to 4 Hours

Over the past month I have been involved in the optimization of a Spatial Index creation/rebuild.  Microsoft has several fixes included in the SQL Server 2012 SP1 CU7 Release I have been asked by several people to tell the story of how I was able to determine the problem code lines that allowed the Spatial…

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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. This post outlines a few of the changes that were made…

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Strange Sch-S / Sch-M Deadlock on Machines with 16 or More Schedulers

Since it took me several days to track down this bug, and I did learn a couple of new things along the way, I thought I would share some of my work. 16 or More CPUS When a system presents SQL Server with 16 or more CPUs, and you are using a high end SQL…

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SQL Server 2012 – True Black Box Recorder

This would be a perfect time to post a blog talking about the new SQL Server 2012 features.  However, I am going to leave that activity to the marketing folks (AlwaysOn, T-SQL Enhancements, …).   I want to talk about something that might not appear on the top of a marketing or sales checklist but for…

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SQL Server: Clarifying The NUMA Configuration Information

The increased number of cores per socket is driving NUMA designs and in SQL Server support we are seeing more NUMA machines and less pure SMP machines.    For whatever reason over the past 2 weeks I have fielded a bunch of questions around NUMA and the information is good for everyone to know so I…

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