Performance

Bojan Petrovic

Optimizing SQL Server index strategies

July 2, 2019 by

Index strategies overview

This article is about techniques for optimizing the SQL Server indexes strategy. It is an appendix of the SQL index overview and strategy article in which I covered different areas like what indexes actually do, how to create them, and I briefly mentioned some index design guidelines. Furthermore, I also presented an example of how to design them by tuning and optimizing queries, so I’ve really tried to cover all but there is always more when it comes to SQL Server indexes.

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Rajendra Gupta
Execution plan and statistics

SQL Server Statistics in Always On Availability Groups

May 27, 2019 by

Introduction to SQL Server Statistics

SQL Server Statistics are an essential part of query performance in SQL Server. They help the query optimizer to prepare a query plan using the distribution of values in participating rows. If we do not have updated statistics, it might lead to resource intensive query execution plan. For example, for a large table having a billion records, SQL may choose to have an index scan instead of an index seek.

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Ed Pollack

Methods to Insert Data into SQL Server

April 10, 2019 by

Summary

There are a variety of ways of managing data to insert into SQL Server. How we generate and insert data into tables can have a profound impact on performance and maintainability! This topic is often overlooked as a beginner’s consideration, but mistakes in how we grow objects can create massive headaches for future developers and administrators.

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Nikola Dimitrijevic

SQL Server trace flags guide; from -1 to 840

March 4, 2019 by

SQL Server trace flags are configuration handles that can be used to enable or disable a specific SQL Server characteristic or to change a specific SQL Server behavior. It is an advanced SQL Server mechanism that allows drilling down into a hidden and advanced SQL Server features to ensure more effective troubleshooting and debugging, advanced monitoring of SQL Server behavior and diagnosing of performance issues, or turning on and off various SQL Server features

Bojan Petrovic

SQL index maintenance

January 23, 2019 by

One of the main DBA responsibilities is to ensure databases to perform optimally. The most efficient way to do this is through indexes. SQL indexes are one of the greatest resources when it comes to performance gain. However, the thing about indexes is that they degrade over time.

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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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Bojan Petrovic

How to collect performance and system information in SQL Server

August 16, 2018 by

In this article, we’re going to through many of the tools we can use for monitoring SQL Server. SQL Server is chock-full of lots of good reports that allows a DBA to quickly spot whether there is any current performance bottleneck on the SQL Server. Many of these sit on top of DMVs but they give us a visually interactive way to look and work with the data. We’re going to start with SQL Server Performance Dashboard Reports.

Dashboard Reports

Let’s jump into SQL Server Management Studio (SSMS) and the first thing we’re going to take you through out-of-the-box dashboard reports of all levels. They can be found by right-clicking the SQL Server instance in Object Explorer, and from the context menu, you’ll find Reports > Standard Reports:

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Nikola Dimitrijevic

SQL Server performance counters (Batch Requests/sec or Transactions/sec): what to monitor and why

June 5, 2018 by

When maintaining SQL Server, it is essential to get an accurate perception of how busy it is. Two metrics that are often considered as indicators of how busy SQL Server is are Batch Requests/sec and Transaction/sec. When those metrics trend higher, they often affect all other metrics and make them go higher as well. While they could look similar, they are using a different type of starting point for measurement; the batches and transactions. So, to correctly understand those important metrics, lets first try to understand what the batches and transactions in SQL Server are and what are the differences between the two

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Dmitry Piliugin

SQL Server NOLOCK and Top Optimization

April 12, 2018 by

Sometimes people use nolock hint as a “turbo” button for their queries, assuming that not taking locks will speed up the query execution. There are many good articles describing all the dangerous moments of this approach, because of the read uncommitted isolation level. However, the focus of this article is a performance problem that you may encounter using nolock hint in some cases.

Let us setup some test data first.

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Dmitry Piliugin

Overpopulated Primary Key and CE Model Variation in SQL Server

April 4, 2018 by

In this blog post, we are going to talk about another cardinality estimation model enhancement in SQL Server 2014 – Overpopulated Primary Key (OPK).

Consider a fact table that contains information about some sales, for example, and a date dimension table. Usually, a fact table contains the data about the current year and past years, but a dimension table usually contains the data for the next few years also.

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