SQL Server 2016 R Services: introduction

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This article is a short introduction to R programming language and a new R Services feature in SQL Server 2016. I hope, it will be a good starting point for those, who haven’t heard about it at all. R is a software environment and programming language for statistical computing, predictive analytics, and rich graphics. R can … Read more

SQL Server Query Plans: Startup Expression Predicate

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I’ve already posted about predicates in query plans, but here is one more: Startup Expression Predicate. Again, it’s better to illustrate its behavior by example. Let’s create a small table with one clustered index and put some data into it. Now, look at the following query. It should calculate the amount of rows in the … Read more

SQL Server Query Plans: Predicates vs. Seek Predicates

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If you have ever written any query with a predicate, you should have noticed, that, at first, the optimizer is trying to find the smallest indexes, and then try to push predicate down to the get data operators to minimize the amount of logical and physical reads. To illustrate this behavior, let’s look at the example … Read more

MAXDOP and Resource Governor in SQL Server

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Many of you at least should have heard about Max Degree of Parallelism setting, which exists in SQL Server from the early versions. By default, its value is zero, which means that SQL Server determines by itself the optimal number of threads for your queries. However, let us go a little bit further and delve … Read more