This month’s TSQL-Tuesday is hosted by Rob Farley (blog | twitter), who became a Microsoft Certified Master this past December (congrats!)....  Read more...

I’m 30 today. In addition, it’s been 10 years since I started working with SQL Server. In my twenties, I fell in...  Read more...

Get a free ebook from Red Gate Software and SQLServerCentral from MVP Grant Fritchey. Learn how to read and interpret execution plans.  Read more...

Every Database Administrator, developer, report writer, and anyone else who writes T-SQL to access SQL Server data, must understand how to read and interpret execution plans. This book leads you right from the basics of capturing plans, through how to interrupt them in their various forms, graphical or XML, and then how to use the information you find there to diagnose the most common causes of poor query performance, and so optimize your SQL queries, and improve your indexing strategy.  Read more...

Table partitioning is a blessing in that it makes large tables that have varying access patterns more scalable and manageable, but it is a mixed blessing. It is important to understand the down-side before using table partitioning.  Read more...

If you’re moving to a fully-fledged SQL database as part of Azure you may never even touch SQL Server Management...  Read more...

Do sub query expressions introduce a performance penalty on retrieving large data sets?  Read more...

I’ve been working with execution plans quite a lot in SQL Server 2012. There are a number of changes, most of them associated with new or different functionality. I had not noticed anything really fundamental until recently. I’ve become a huge proponent of always checking the properties of the SELECT statement. There’s so much useful information in there about what’s happened with the plan generation in the optimizer (not low level stuff, but the big picture items) that you should always be checking it first as a fundamental part of your plan examinations.  Read more...

There's more information hidden behind those graphical plans than you might first suspect.  Read more...

Are your index statistics up to date? The SQL Server database engine uses statistics to determine which execution plan to use when a query is compiled. Index statistics are used to help the SQL Server engine determine the cardinality of different column values in a SQL Server table. If you want to give SQL Server a fighting chance at picking an optimal execution plan then you need to make sure you maintain your index statistics.  Read more...

This free book is brought to you by Red Gate Software and Simple Talk Publishing. Why my query is running slow? Why isn't my index getting used? In order to answer these questions, you have to ask the same return question in each case: have you looked at the execution plan? Grant Fritchey provides the only dedicated and detailed guide to this essential topic.  Read more...

When Fabiano agreed to undertake the epic task of describing each showplan operator, none of us quite predicted the interesting ways that the series helps to understand how the query optimizer works. With the Merge Interval, Fabiano comes up with some insights about the way that the Query optimizer handles overlapping ranges efficiently.   Read more...

Did you ever wonder how and why your indexes affect the performances of joins? Once you've read Fabiano Amorim's unforgettable explanation, you'll learn to love the MERGE operator, and plan your indexes so as to allow the Query Optimiser to use it.   Read more...

In this article Brian Ellul explorea how it's possible to eliminate the SORT operator (and its performance cost) on performing SELECTS statements.  Read more...

Do sub query expressions introduce a performance penalty on retrieving large data sets?  Read more...

Fabiano continues in his mission to describe the major Showplan Operators used by SQL Server's Query Optimiser. This week he meets a star, the Key Lookup, a stalwart performer, but most famous for its role in ill-performing queries where an index does not 'cover' the data required to execute the query. If you understand why, and in what circumstances, key lookups are slow, it helps greatly with optimising query performance.   Read more...

A review of MVP Grant Fritchey's "Dissecting Execution Plans". This is one book that you'll want on your bookshelf.  Read more...

The Query Optimizer gets it right most of the time, but occasionally it chooses a plan that isn't the best possible. You can give the Query Optimiser a better idea by using Table, Join and Query hints. These come with a risk: Any choices you force on the Optimizer by using hints can turn out to be entirely wrong as the database changes with the addition of data over time. Grant Fritchey, in a chapter from his highly acclaimed book, explains further.  Read more...

Another frequently heard story is that stored procedures get and reuse execution plans, but ad hoc queries do not. A...  Read more...