In my previous post, I explained the basic of parameter sniffing, and then built on that to explain the lesser known mechanics of variable sniffing and cardinality sniffing. However, I also sneakily inserted a few comments on misconceptions about the performance impact of parameter sniffing, with the promise to explain in more detail later. Well … ...

Your SQL Server instances, like people with hay fever that forget to take their antihistamines during summer, is sniffing all the time. Sniffing is a trick employed by the optimizer in an attempt to give you better execution plans.   The most common form of sniffing is parameter sniffing. Many people know about parameter sniffing, but there ...

  Just a quick note that my CTP3 paper has finally been published, and now I can start working on the final version! Here’s the link: http://download.microsoft.com/download/D/5/2/D52D374F-D442-4275-B570-0EB527102F4D/SQL_Server_In_Memory_OLTP_Internals_Overview_for_SQL_Server_2016_CTP3_EN_US.pdf Enjoy! ~Kalen

As I mentioned in my previous post, I am heading in new directions, and the first goal has now been reached. Rather than working with training companies to offer my SQL Server Internals training, I am now partnering with Denny Cherry and Associates to offer a special opportunity to those wanting to experience a multi-day training event with ...

Originally appearing in my monthly column at Database Trends & Applications magazine. When it comes to cloud-based database management, there are really only two players: Amazon, the value leader, and Microsoft, the innovation leader. Amazon has carved out a niche as the value leader in cloud-based database management, ...

Here are some oldies, but goodies that I recommend you read:Two Partitioning Peculiarities and Aggregates and PartitioningMost of us know that partitions are one of the best ways to scale very large databases or very large IO workloads.  However, there are risks, two of which are explored in detail by internals master Paul White ...

Aaron Bertrand (b | t) is on a roll this month's SQL Server performance highlights with more great articles from SQLPerformance.com. Troubleshooting AlwaysOn – Sometimes it takes many sets of eyesAaron Bertrand (b | t) hit some obstacles recently when configuring an Availability Groups lab environment. This post ...

Don't miss these great articles on SQLPerformance.com from the industry’s top experts:A Look At DBCC CHECKCONSTRAINTS and I/OErin Stellato (b | t) of SQLskills takes a deep look into the I/O impact of running DBCC CHECKCONSTRAINTS, including explaining why some check methods may consume a lot more I/O than others.The ...

Over the years I have spent working with SQL Server, the personal time investment that has repaid itself more than any other is becoming intimately familiar with execution plans and how they can be used to diagnose and correct performance problems. There is nothing I enjoy more than talking about execution plans, the query optimizer, and how ...

And it coincides with a new book of mine being published. So I decided I would give away some presents! Today marks 27 years that I have been working with SQL Server. On this day in 1987 I started working for the Sybase Corporation in Berkeley, California, and SQL Server has consumed by working life, ever since…. I still have quite a few copies ...