Books by Grant Fritchey

If a query is performing poorly, and you can't understand why, then that query's execution plan will tell you not only what data set is coming back, but also what SQL Server did, and in what order, to get that data. It will reveal how the data was retrieved, and from which tables and indexes, what types of joins were used, at what point filtering, sorting and aggregation occurred, and a whole lot more. These details will often highlight the likely source of any problem. I wrote this book with the singular goal of teaching you how to read SQL Server Execution plans It will explain, among many other things, the following: How to capture execution plans using manual and automatic methodsA documented method for reading and interpreting execution plansHow common SQL Server objects, such as indexes, views, stored procedures, and so on, appear in execution plansHow to control execution plans with hints and plan guides, and why this is a double-edged swordHow the Query Store works with, and collects data on, execution plans With this knowledge, you'll have everything you need to read the execution plan, for any query of your own, regardless of complexity, and understand what it does and what is causing the bad performance. It is still your job to work out how best to fix it, but your new understanding of execution plans will give a much better chance of success!

Every day, out in the various online forums devoted to SQL Server, and on Twitter, the same types of questions come up repeatedly: Why is this query running slowly? Why is SQL Server ignoring my index? Why does this query run quickly sometimes and slowly at others? My response is the same in each case: have you looked at the execution plan? An execution plan describes what's going on behind the scenes when SQL Server executes a query. It shows how the query optimizer joined the data from the various tables defined in the query, which indexes it used, if any, how it performed any aggregations or sorting, and much more. It also estimates the cost of all of these operations, in terms of the relative load placed on the system. 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. My 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.