At the end of May 2017, Paul and I had a discussion about SOS_SCHEDULER_YIELD waits and whether or not they could become skewed in SQL Server as a result of hypervisor scheduling issues for a VM running SQL Server.  I did some initial testing of this in my VM lab using both Hyper-V and VMware […]

Tracking Compiles with Extended Events

This post comes from a question by Tara Kizer on DBA StackExchange related to Compilations/Sec in PerfMon and using Extended Events to try and track the compilations that were happening in SQL Server for one of their clients.  There are a number of events in Extended Events that relate to plans in SQL Server, and […]

Looking at Non-Updating Updates with Extended Events

For a few weeks now, there has been a long running thread on SQL Server Central about UPDATE operations that don't perform any changes because the statement sets a column to the same value as already exists in the row.  While I believe that one of the posters is incredibly snarky and outright rude to […]

Identifying External Memory Pressure with dm_os_ring_buffers and RING_BUFFER_RESOURCE_MONITOR

In my last blog post, I provided a script that queried the XML for the resource monitor ring buffer entries in sys.dm_os_ring_buffers to identify when the system was under memory pressure as a result of not having the ‘max server memory’ sp_configure option set correctly for the server. Since that post has gone live, I’ve […]

Wow… An online calculator to misconfigure your SQL Server memory!

Properly configuring SQL Server is an important factor in having a stable environment that performs well.  While there is a lot of good guidance available for how to best configure SQL Server, the specifics of any given implementation is a very big “It Depends…” and one of the things that we do in our Immersion […]

Tracking Problematic Pages Splits in SQL Server 2012 Extended Events – No Really This Time!

Just over a year ago I blogged about the enhancements that were made to the sqlserver.page_split Event in SQL Server 2012 to make it easier to identify what the splitting object was and the type of split that was being performed.  Sadly what I discovered writing that post was that even with the extra information […]

SQL Server and Soft NUMA

Friday of last week, Steve Jones (Blog|Twitter) asked a question on the Twitter #sqlhelp tag about SQL Server and Soft NUMA that prompted me to write the long waiting follow up to my first post Understanding Non-Uniform Memory Access/Architectures (NUMA). The question that Steve asked was: @way0utwest: “Do you always have one soft NUMA node? […]

Looking at multiple data files and proportional fill with Extended Events

At SQL Connections, I presented a session titled “Learn SQL Server Internals with Extended Events” where I demonstrated a number ways to use Extended Events to learn about the internal workings of the database engine for SQL Server.  The morning of the session I was chatting with someone about a problem they had seen and […]

TSQL Tuesday #11 – Misconceptions – The Tempdb Log File and VLF Counts

This post is part of the monthly community event called T-SQL Tuesday started by Adam Machanic (blog|twitter) and hosted by someone else each month. This month the host is Sankar Reddy (blog|twitter) and the topic is Misconceptions in SQL Server. You can follow posts for this theme on Twitter by looking at #TSQL2sDay hashtag. It […]

Does tempdb Get Recreated From model at Startup?

In my last post Does the tempdb Log file get Zero Initialized at Startup? I questioned whether or not tempdb is actually created from the model database or not at startup.  There is actually an easy way to prove that this statement, at least internally to the tempdb database is in fact TRUE.  Many thanks […]