Performance

Prashanth Jayaram

Top 8 new (or enhanced) SQL Server 2017 DMVs and DMFs for DBAs

January 17, 2018 by

Dynamic management views (DMVs) and dynamic management functions (DMFs) are system views and system functions that return metadata of the system state. On querying the related system objects, database administrators can understand the internals of SQL Server. It allows us to monitor the performance of the SQL Server instance, and diagnose issues with it.

SQL Server 2017 ships with a number of new and enhanced dynamic management views and dynamic management functions that will help DBAs monitor the health and performance of SQL Server instances. A few existing DMV’s such as sys.dm_os_sys_info and sys.dm_db_file_space_usage have been enhanced. Some have also been newly built and available only for SQL Server 2017.

Read more »
Esat Erkec

How to use sargable expressions in T-SQL queries; performance advantages and examples

December 22, 2017 by

The challenge

One of the main tasks of a SQL Server database administrator is performance tuning. Sometimes, though, coders or developers don’t always prioritize database performance or query optimization. Here is a typical scenario

  • Imagine that developers create a new table and then insert some records in a test environment and test their queries to retrieve data from it
  • The query executed successfully and does not exhibit any symptoms of performance problems
  • The developer team release this table and query into production
  • One day you take a telephone from your colleague and he says my report is very slow
  • Bingo! In production, this table contains a lot of records and this is resulting in performance bottlenecks when querying it
Read more »
Neeraj Prasad Sharma
C:\Users\Neeraj\Desktop\TOP\IMAGES\FinalSerialNL.JPG

SQL Server TOP clause performance problem with parallelism

April 13, 2017 by

Basics of TOP Operator

The TOP keyword in SQL Server is a non-ANSI standard expression to limit query results to some set of pre-specified rows. As an argument, it takes 0 to positive Bigint (9223372036854775807) and anything beyond or less gives an error message. TOP without an order by clause, in production, seems buggy because it can produce results in any order depending on the current schema and execution plan. You can also specify a percent with TOP expression which returns only the expression percent of rows from the result set. Float expressions used in TOP percent are rounded up to the next integer value.

Read more »

Some uncommon but useful T-SQL and Database Engine Enhancements in SQL Server 2016

March 20, 2017 by

SQL Server 2016 is the most advanced version of Microsoft’s Data Platform released yet. This is obviously my favorite one as it has tremendous capabilities and enormous features. These new additions not only enhance the productivity of its users (Database Developer, DBA or Application Developer), but also enable the enterprise to use its data more effectively and efficiently.

Read more »
Mustafa EL-Masry

How to analyze Storage Subsystem Performance in SQL Server

February 23, 2017 by

Introduction

To improve performance, it is common for DBAs to search in each aspect except analyzing storage subsystem performance even though in many times, issues are, in fact, caused by poor storage subsystem performance. Therefore, I want to give you some tools and recommendation that you can use it to prevent your storage subsystem from being a performance issue for you.

Read more »
Ahmad Yaseen

Indexing SQL Server Temporary Tables

January 31, 2017 by

SQL Server Temporary tables are a special type of tables that are written to the TempDB database and act like regular tables, providing a suitable workplace for intermediate data processing before saving the result to a regular table, as it can live only for the age of the database connection.

Read more »
Ed Pollack

SQL Server Job Performance – Reporting

January 19, 2017 by

Description

Once collected, job performance metrics can be used for a variety of reporting needs, from locating jobs that are not performing well to finding optimal release windows, scheduling maintenance, or trending over time. These techniques allow us to maintain insight into parts of SQL Server that are often not monitored enough and prevent job-related emergencies before they become emergencies.

Read more »
Ed Pollack

SQL Server Job Performance – Tracking

January 19, 2017 by

Description

Keeping track of our SQL Server Agent jobs is a very effective way to control scheduling, failures, and understand when undesired conditions may be manifesting themselves. This is a brief journey towards a solution that provides us far greater insight into our jobs, schedules, and executions than we can glean from SQL Server by default.

Read more »
Daniel Calbimonte

SQL Server performance myth busters

December 21, 2016 by

Introduction

In this article, we will verify if the following statements are true or they are just myths:

  1. Truncate is faster than a delete and it consumes less space in the logs
  2. Do not use cursors to Create or drop multiple objects because it is very slow
  3. Do not use cursors to convert or process row values because it is very slow
Read more »
Sifiso W. Ndlovu

Top 5 New SQL Server 2016 DMVs for DBAs

December 20, 2016 by

Since its initial release that was part of SQL Server 2005, Dynamic Management Views (DMV) changed – mostly for the better – the role of database administration (DBA) within SQL Server-based environments. They improved the efficiency of DBAs regarding database server monitoring, issue diagnoses, and subsequent performance optimisation. As a result of this positive reception, it has become customary that some of the highly anticipated items in every release of SQL Server includes discovering what new DMVs will be added. In this article I take you through my favourite top 5 DMVs to come out of SQL Server 2016.

Read more »
Daniel Calbimonte

3 ways to improve T-SQL performance

November 22, 2016 by

Introduction

When customers used to ask for advice to solve some T-SQL Problem, they would show me their scripts, stored procedures and cursors. I saw horrible things doing that job, some things I do not want to remember, and even some I cannot tell you about 😉 In this article, we will talk about performance problems when using while loops in T-SQL. We will also talk about problems with UNIONsand finally the use of JOINS of two or more tables using the where clause (ANSI 89) instead of using INNER, LEFT or RIGHT JOINS using the from clause (ANSI 92).

Read more »
Ahmad Yaseen

What’s new in SQL Server 2014 Cardinality Estimator?

November 14, 2016 by

The Cardinality Estimator is a SQL Server Query Processor component that is responsible for predicting the number of rows that the query will return. This estimation of the number of rows in addition to the SQL Server statistics will be used by the SQL Server Query Optimizer to create the optimal and the most accurate execution plan for your query that has the lowest processing cost to execute.

Read more »
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 »
Page 1 of 212