Reading Query Plans with the Showplan Options

This post is about the several ways of reading the query plan (called the showplan options). Now that we know what a query plan is, why it’s helpful and what it consists of (iterators), let’s find out how we can read the query plans in SQL Server. I believe most of you are familiar with Read More


Properties of Iterators

In this post I will continue the discussion about iterators in the context of a query execution plan. This time, I will tell you about some of their most important properties and the things to take into consideration when investigating the performance of an execution plan.


Iterators in the Query Execution Plan

In this article I will explain the concept of iterators, in the context of the query execution plan. First, you will find out what they are. Second, I will tell you what are the main actions performed by an iterator. And last, but not least, I am going to show you how they work in Read More


Query Execution Engine Introduction

This is the first post from my complex tutorial project called “Understanding Query Execution Plans”. This is an introductory post, in which I will  guide you through the concepts you need to know before starting to analyze the plans. 


SQL Quiz #10 – The OUTPUT Clause

The OUTPUT clause is supported in T-SQL for modification statements, which you can use to return information from modified rows. This clause, even if not as popular as others, is useful in multiple scenarios, for example: for auditing purposes confirmation messages archiving your data It can be used to return information about every row affected Read More