Performance

Ahmad Yaseen

SQL Server 2016 Parameter Sniffing

October 19, 2016 by

SQL Server tries always to generate the most optimized execution plan for each stored procedure the first time that the stored procedure is executed. The SQL Server Engine looks at the stored procedure passed parameter values when compiling the stored procedure, the first execution, in order to create the optimal plan including the parameters and keep that plan for future use in the plan cache. This parameter analysis process is called the Parameter Sniffing.

Read more »
Ahmad Yaseen

Troubleshoot SQL query performance using SQL Server 2016 Live Execution Statistics

August 19, 2016 by

SQL Server Management Studio a graphical interactive that allows you to interact with the databases hosted on your servers. SSMS provides you with the ability to write, edit, execute, analyze and monitor your SQL queries. It also helps database administrators answer important questions about the SQL query performance, such as why a query is slow or why an index is not used. The answer to these questions can be found simply by tracking the Query Execution Plan.

Read more »
Ahmad Yaseen

SQL Server 2016 Trace flags modifications

August 9, 2016 by

SQL Server Trace Flags are special switches that are used to customize and control specific behaviors of the SQL Server Engine. Trace Flags can be defined in two forms; Session Trace Flags that are activated and visible at the current connection level only, and Global Trace Flags that are enabled and visible at the SQL Server Instance level and applied to all connecting sessions in that SQL Server. Global Trace Flags should be enabled globally in order to take effect, where some Trace Flags that can be either Global or Session Trace Flags can be enabled in the appropriate scope, and its effect will appear on the defined level.

Read more »
Ahmad Yaseen

The SQL Server 2014 Resource Governor

July 15, 2016 by

SQL Server Resource Governor was introduced in SQL Server 2008. This feature is used to control the consumption of the available resources, by limiting the amount of the CPU, Memory and IOPS used by the incoming sessions, preventing performance issues that are caused by resources high consumption.

Read more »
Daniel Calbimonte

Is this the end of SQL Profiler?

June 13, 2016 by

Introduction

SQL Server Profiler is still a tool used to monitor our relational databases and our multidimensional ones. We used for performance and security purposes. However, in the SQL Server 2016, they announced that the SQL Profiler will be deprecated in future versions.

Read more »
Ed Pollack

Insight into the SQL Server buffer cache

February 18, 2016 by

When we talk about memory usage in SQL Server, we are often referring to the buffer cache. This is an important part of SQL Server’s architecture, and is responsible for the ability to query frequently accessed data extremely fast. Knowing how the buffer cache works will allow us to properly allocate memory in SQL Server, gauge accurately how databases are accessing data, and ensure that there are not inefficiencies in our code that cause excessive data to be cached.

Read more »
Kimberly Killian

What is causing database slowdowns?

February 2, 2016 by

Why is my database so slow? This query used to be so much faster. Why does it take so long to rebuild my index? How come it was fine last month? Every day I am asked these types of questions by clients. Every day! A lot of database developers and application developers do not realize that indexes are ever changing entities within your database or rather they need to be monitored closely and managed periodically to remain efficient. I cannot even count the times someone tells me “but we have index’s on this or that column and it was fine last month” and so on. All while they fail to realize or even tell me that the database just took on, updated or deleted 1,000,000 records for example, which would definitely change the footprint of the data, making the index’s unsound or in need of help. Even adding 50 new users that use the data differently could require new indexes. That being said, I decided to automate a quick and easy data gathering and reporting job that helps to answer these questions. Most of the time query performance questions can be answered by determining the fragmentation levels of index’s, if there are missing index’s, duplicate index’s, unused index’s and what are the heavy hitters in regards to queries and are queries running in memory or to disk and how many executions. My favorite thing to do with SQL Server is automate, automate and automate the tasks that are asked of me over and over.

Read more »
Miroslav Dimitrov

Tips and tricks for SQL Server database maintenance optimization

January 11, 2016 by

Database maintenance is very important, a critical part of our database administrators’ daily tasks. However, this aspect is frequently underestimated which could lead to performance problems and respectively angry, unhappy customers. In this article, we will take a look at the different maintenance operations we have in SQL Server and how we can optimize them and take the maximum out of each.

Read more »
Eli Leiba

Creating an automatic View to an In-line table function conversion stored procedure

December 22, 2015 by

Introducing the Problem

We have a series of views in our organization’s application database. The views definitions are all static queries that consist of few or many condition clauses.

When the application first started with the initial data, the views operated normally, but after a while, after a period where data volume increased, the application’s performance time, through the views usage, degraded.

Read more »
Ed Pollack

Filtered indexes: Performance analysis and hidden costs

December 11, 2015 by

Introduction

Filtered indexes are well documented, as they have been around in SQL Server for almost six years now. Despite their longevity and usefulness, discussions of them tend to be very simple overviews using simple queries and not digging too deeply into more precise costs and benefits. This article is inspired by a production problem that cropped up recently involving a filtered index that illustrated that general knowledge of their function was not as complete as it should have been.

Read more »
Milena Petrovic

Inaccurate SQL Server statistics – a SQL query performance killer – updating SQL Server statistics

April 28, 2014 by
As shown in the previous part of this series, inaccurate statistics can degrade SQL Server performance. We described how to work with SQL Server statistics using SQL Server Management Studio options and T-SQL. In this article, we will show how to update SQL Server statistics, what are the updating costs, and when updating is recommended. Read more »
Milena Petrovic

SQL Server alerts in troubleshooting performance issues: SQL Server alerting basics

March 14, 2014 by

Why is SQL Server alerting important?

To be aware of what’s going on with your system and how SQL Server performs, monitoring is necessary. However, just monitoring might not be enough. Being notified about a performance issue whenever a specific SQL Server counter meets a threshold value, or a specific event occurs, boosts monitoring usability. These notifications enable DBAs to be aware of every important system performance change as soon as it happens, and therefore they can act immediately to fix the issue and prevent further problems Read more »
Milena Petrovic

Troubleshooting SQL Server issues with sys.dm_os_performance_counters

March 13, 2014 by

sys.dm_os_performance_counters

sys.dm_os_performance_counters is a system Dynamic Management View (DMV) that returns one row for each SQL Server performance counter. It’s useful for obtaining information about current performance counter values. These counter values are also shown in Windows Performance Monitor, besides other operating system counters Read more »