SOS_SCHEDULER_YIELD waits and the LOCK_HASH spinlock

Continuing my series on advanced performance troubleshooting – see these two posts for the scripts I’ll be using and an introduction to the series: Wait statistics, or please tell me where it hurts Advanced performance troubleshooting: waits, latches, spinlocks In this blog post I’d like to show you an example of SOS_SCHEDULER_YIELD waits occurring and […]

Patent surprise

I was searching around in the US Patent Office database this evening to find my patent for consistency checking of a backup without restoring the backup, for a Twitter conversation I was having, when I discovered that another one I filed before leaving Microsoft was granted in late 2009. The new one was part of […]

Anonymous survey: salaries in the SQL Server world

Following my survey on company and employee loyalty, job security, and retention, I think it'll be very useful to the community to do a survey on salary vs experience for the SQL Server world – so here it is! This survey is completely anonymous – there is no way for anyone to know what you voted. […]

Job security, loyalty, and employee retention: you need to take control

  (Used with permission from It's an interesting marketplace for DBAs right now. Depending on who you speak to, and what your view into the DBA world is, a few data points are evident: There's a view that all the good people already have jobs There's a view that it's pretty hard right now […]

Survey: how much server memory is being wasted? (code to run)

In this survey I'd like you to run some code and then send me the results (and I'm sure someone will put together a PowerShell script to make it easy to run on multiple instances). I want to know how much of your precious server memory is being wasted storing empty space on data file […]

Advanced SQL Server performance tuning

(Check out my Pluralsight online training course: SQL Server: Performance Troubleshooting Using Wait Statistics¬†and my¬†comprehensive library of all wait types and latch classes.) It’s all very well having whizz-bang 3rd-party performance monitoring and troubleshooting tools, but sometimes you have to get deeper into what’s going on with SQL Server than any of these tools can […]

How to download a sqlservr.pdb symbol file

I just had to figure out how to do this so I figured a quick blog post is in order to save other people time in future. If you ever need to use windbg to debug a SQL Server crash dump, or you want to capture call stacks using extended events (e.g. when debugging excessive […]

How to examine IO subsystem latencies from within SQL Server

(Check out our Pluralsight online training course: SQL Server: Improving Storage Subsystem Performance.) Edit: I blogged an update script to capture a snapshot of I/O latencies in this blog post. Over the last few months I’ve been lecturing at classes and conferences about getting SQL Server’s view of the I/O subsystem and what latencies it […]

TechNet Magazine article: data protection and the corporate jigsaw puzzle

My latest feature article for TechNet Magazine has just been published in the April edition. It focuses on planning an HA/DR strategy within the confines of a larger corporate IT strategy, from multiple perspectives but really focusing on the IT manager role and how to interact both up (to business managers) and down (to DBAs). […]

Surveys: what’s your company doing for you, and vice versa?

After a discussion on Twitter this morning, my good friend Steve Jones (blog|twitter) said it would be great to have a survey polling people on how their companies are retaining them this year, and vice-versa – so here it is! The survey is completely anonymous, so don't be afraid to answer. Also, if you'd like to […]

Survey results: Common causes of performance problems

A couple of week ago I kicked off a survey about common causes of performance problems – see here for the survey. Firstly I asked what was the root cause for the most recent performance problems you looked at – here are the results:   Secondly I asked what you think the overall most common […]

Beware of advice from 3rd-party tools around dropping indexes

(In this post I'm not going to name-and-shame, as I'm sure the problems will be fixed in time.) I want to warn you about unthinkingly acting on advice from 3rd-party tools around dropping nonclustered indexes. One of my long-term clients recently bought and installed a new tool and has been asking me about recommendations from […]