I'm doing two new webcasts next week on Wednesday, December 19th, one in the morning and the other after lunch.   SSDs are a Game Changer for SQL Server Storage No, session is not exclusively about SSDs.  But this is my first session on IO and storage tuning that emphasizes SSDs over hard disks.  As Bob Dylan said ''Times, they ...

Recently sp_blitz procedure on one of my OLTP servers returned alarming notification about high latency on one of the disks (more than 100ms per IO). Our chief storage guy didn’t understand what I was talking about – according to his measures, average latency is only about 15ms. In order to investigate the issue, I’ve recorded 2 snapshots of ...

Summary: A deep dive into SQL Server parallelism, and a potential performance problem with parallel plans that use TOP. There was an interesting question asked by Mark Storey-Smith on dba.stackexchange.com back in October 2011.  He was looking at the execution plan for a query that counts a million rows from a virtual auxiliary table of ...

One last reminder -  If you're interested in learning more about troubleshooting and optimizing SQL Server performance, please consider coming to the full-day seminar I'll be giving this Friday.  Full details are here: http://sqlperftuning.eventbrite.com/.  We'll be working some exercises, so bring your laptop with an instance ...

The following table summarizes the results from my last two blog entries, showing the CPU time used when performing 5 million clustered index seeks: In test 1, making the clustered index unique improved performance by around 40%. In test 2, making the same change reduced performance by around 70% (on 64-bit systems – more on that later).  ...

Remote Desktop Services Component Architecture Poster Grab your own poster! A visual guide to key Remote Desktop Services technologies in Windows Server 2008R2     Virtually Free Get the latest update rollup package for the Hyper-V role in Windows Server 2008 R2 and be sure to bookmark the Windows Virtualization ...

You probably already know that it’s important to be aware of data types when writing queries, and that implicit conversions between types can lead to poor query performance.  Some people have gone so far as to write scripts to search the plan cache for CONVERT_IMPLICIT elements, and others routinely inspect plans for that type of thing when ...

I profiled Adam Machanic's (blog | twitter) excellent stored procedure, SP_WHOISACTIVE, back in August of 2010 in my monthly SQLMag column, Tool Time.  Adam has been diligent about maintaining the tool and adding new features. Read the details on my SQLMag Tool Time column (here - ...

From BOL, "Key-Range Locking" article: Key-range locks protect a range of rows implicitly included in a record set being read by a Transact-SQL statement while using the serializable transaction isolation level. The serializable isolation level requires that any query executed during a transaction must obtain the same set of rows every ...

Back in late May, my pal Buck Woody (blog | twitter) and I presented SQL Server for the Oracle DBA.  Buck played Jerry Lewis' role, while I played the straight man a la Dean Martin.  You can see the recording and slide deck here.  Since both Buck and I spent a considerable number of years working on Oracle, we felt like we had ...