Execution plans

Ahmad Yaseen

SQL Execution Plan enhancements in SSMS 18.0

November 13, 2018 by

This article will provide an overview of the SSMS 18.0 with particular focus on improvements to the SQL execution plan feature. To work with Microsoft SQL Server Database Engine, you need to have an environment to edit, debug and deploy scripts written in different languages such as T-SQL, DAX, MDX, XML and JSON. In addition, you need a GUI tool that helps you to configure, query, monitor and administrate your SQL Server instances wherever they are hosted; locally at your machine, on a remote Windows or Linux server or in the cloud. All this can be achieved using SQL Server Management Studio aka SSMS.

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Ahmad Yaseen

SQL Server Execution Plan Operators – Part 4

October 29, 2018 by

In the previous articles of this series, we went through three sets of SQL Server Execution Plan operators that you will meet with while working with the different Execution Plan queries. We described the Table Scan, Clustered Index Scan, Clustered Index Seek, the Non-Clustered Index Seek, RID Lookup, Key Lookup, Sort, Aggregate – Stream Aggregate, Compute Scalar, Concatenation, Assert, Hash Match Join, Hash Match Aggregate , Merge Join and Nested Loops Join Execution Plan operators. In this article, we will dive in the fourth set of these SQL Server Execution Plan operators.

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Ahmad Yaseen

SQL Server Execution Plan Operators – Part 3

October 29, 2018 by

In the previous articles of this series, we discussed a group of SQL Server Execution Plan operators that you will face when studying the SQL Execution Plan of different queries. We showed the Table Scan, Clustered Index Scan, Clustered Index Seek, the Non-Clustered Index Seek, RID Lookup, Key Lookup and Sort Execution Plan operators. In this article, we will discuss the third set of these SQL Execution Plan operators.

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Ahmad Yaseen

SQL Server Execution Plan Operators – Part 2

October 26, 2018 by

In the previous article, we talked about the first set of operators you may encounter when working with SQL Server Execution Plans. We described the Non Clustered Index, Seek Execution Plan operators, Table Scan, Clustered Index Scan, and the Clustered Index Seek. In this article, we will discuss the second set of these SQL Server execution plan operators.

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Ahmad Yaseen

SQL Server Execution Plan Operators – Part 1

September 12, 2018 by

In the previous articles of this series, SQL Server Execution Plans overview , SQL Server Execution Plans types and How to Analyze SQL Execution Plan Graphical Components, we discussed the steps that are performed by the SQL Server Relational Engine to generate the Execution Plan of a submitted query and the steps performed by the SQL Server Storage Engine to retrieve the requested data or perform the requested modification operation.

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Ahmad Yaseen

How to Analyze SQL Execution Plan Graphical Components

September 7, 2018 by

In the previous articles of this series, SQL Server Execution Plans overview and SQL Server Execution Plans types we went through the different stages that the submitted SQL Server query followed and how it processed by the SQL Server Relational Engine that generates the Execution Plan and the SQL Server Storage Engine that performs the requested data retrieval or modification operation. In addition, we described deeply the different types and formats of the SQL Server Execution Plans that can be used for queries performance troubleshooting purposes. In this article, we will discuss the graphical query plan components and how to analyze it.

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James Rhoat

Performance troubleshooting when the query plan from the application is different than SSMS

August 24, 2018 by

Troubleshooting performance issues in a database is one of the main jobs of DBAs and by now most can trace the problem back to a query which is either running to slow or is causing a blocking issue on a key table. However, what is often not known is why this doesn’t cause problems in SSMS or why you don’t get the same query plan as what is inside the app. For example, in your extended event trace you see the query running longer from the application when compared to SSMS.

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Ahmad Yaseen

SQL Server Execution Plans types

July 23, 2018 by

In the previous article, we described, in detail, the different stages that a submitted SQL Server query goes through and how it processed by the SQL Server Relational Engine. The SQL Server Relational Engine generates the Execution Plan and the SQL Server Storage Engine performs the requested data retrieval or modification process. In this article, we will discuss the different types and formats for SQL Server Execution Plans.

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Esat Erkec

Main Concepts of SELECT operators in SQL Server execution plans

July 9, 2018 by

One of the main responsibilities of a database administrator is query tuning and troubleshooting query performance. In this context, SQL Server offers several tools to assist. But among them, query execution plans are essential for query optimization because they include all of the vital information about the query execution process. At the same time as it provides this valuable information “under the hood”, SQL Server creates a graphical description of the execution plan. Read more »

Ahmad Yaseen

SQL Server Execution Plans overview

July 4, 2018 by

In this series of articles, we will navigate the SQL Server Execution Plan ocean, starting from defining the concept of the Execution Plans, walking through the types, components and operators of Execution Plans analyze execution plans and we’ll finish with how to save and administrate the Execution Plans.

When you submit a T-SQL query, you tell the SQL Server Engine what you want, but without specifying how to do it for you. Between submitting the T-SQL query to the SQL Server Database Engine and returning the query result to the end user, the SQL Server Engine will perform four internal query processing operations, to convert the query into a format that can be used by the SQL Server Storage Engine easily use to retrieve the requested data, using the processes assigned to the SQL Engine from the Operating System to work on the submitted query.

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Thomas LeBlanc

Performance tuning – Nested and Merge Loops with Execution Plans

April 2, 2018 by

Even though reading execution is technical, it is more an art than science. The main iterator used when joining tables is a Loop. Nested and Merge loops are 2 of the most common. A plan can even have a loop without joining tables when a Seek needs a Lookup to find additional columns. This art of reading execution plan loops can help with performance tuning and debugging T-SQL. Once over the hump of reading a plan, going from beginner to intermediate is simple.

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Ayman Elnory

SQL Server Query Execution Plans for beginners – Clustered Index Operators

March 5, 2018 by

We have discussed how to created estimated execution plans and actual execution plans in various formats in my previous article SQL Server Query Execution Plan for beginners – Types and Options.

In this article we will continue discussing the various execution plan operators related to clustered indexes, and what they do, when do they appear and what happens when they do.

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