John Deardurff

SQL Skills Blackbelt on SQL Server 2019

Extremely rewarding to be only the 46th person to earn this demanding badge from SQL Skills. It is only achieved after attending SEVEN deeply technical courses focused on Microsoft SQL Server. In total, these courses provide over 155 hours of content and demonstrations.


SQL Server Technical Reviewer

After several attempts, I finally got to see my name in an actual published book. Not as an author but a technical reviewer of the SQL Server 2022 Performance Tuning book written by Grant Fritchey. I have been reading every version of this book since at least the second edition…


Query Optimizer Phases

The SQL Server Query Optimizer uses cost-based optimization to create an execution plan with the least cost.



The SQL Server Database Engine

The three parts of the SQL Server database engine with a focus on how the SQL Server Operating System (SQLOS) component manages resources.


How I spent my Summer Vacation 2019

I just realized that I have not written a blog post since the beginning of May. Instead of backfilling let’s just start again here towards the end of September. First, the big news. After 17 years as a Senior Technical Instructor for New Horizons, I made the decision to make…


SQL Query Processing

How SQL Queries are processed by the Relational Engine. Parsing, Resolving, Optimizing, Compiling, and Executing to return SQL Sets.


Writing T-SQL Videos

In late 2018, I recorded a series of videos for APRESS publishing on how to write T-SQL Queries. (I have linked to the O’Reilly website below.) There are four titles in the series with each title about 45 minutes in length. The first is how to write a T-SQL SELECT…