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How to Find SQL Server Performance Bottlenecks and Fix These Issues


SQL Server is undoubtedly a popular way to manage database. Due to its efficiency, business organizations largely depend on this for data management. This dependency often causes performance bottlenecks and ultimately hampers the productivity of the organization itself. So, it is important to find the bottlenecks and avoid them at any cost. Read on to know everything you need to know about SQL Server bottlenecks, including how to find SQL Server performance bottlenecks. First, we will see the definition of SQL Server bottlenecks.

What is Bottleneck in SQL Server

The term bottleneck means the neck of a bottle that reduces the flow from the bottle. Similarly, SQL Server bottleneck means reduction in the performance of SQL Server. This situation usually occurs when any shared resources like SQL database is concurrently accessed by too many people. Though bottlenecks are inevitable in every system, it should be addressed to save users from loss of time and effort.

Symptoms of SQL Server Bottleneck

If you have this question in mind, how to find out if SQL having bottlenecks or not, here is the answer. First, you have set a certain standard for the performance and then consider the symptoms according to that baseline. This baseline will help you to determine the bottlenecks and low activity period, as well as to compare the effects of the alteration made. That is why, setting up a good baseline is important. Here are the symptoms you need to consider:

  • Disk Bottleneck
    If the SQL Server is having slower response time or the disk counters are operating close to maximum values for a longer period of time, it is having bottlenecks. In such cases, users will also get relevant error messages in SQL application log and hear noises coming from the disks.
  • Memory Bottleneck
    If the application log contains certain messages like out of memory and memory resource timeout, the memory bottleneck is to blame. Some of the other symptoms of Memory bottleneck are increased query execution time, decreased active queries, low buffer cache hit ratio, higher I/O usage, slow system, and low page life expectancy.
  • CPU Bottlenecks
    This type of the bottleneck is easiest to find out. In this case, CPU will be highly utilized by the SQL Server all the time but have low overall throughput
  • How to Identify SQL Server Bottleneck Using Tools

    Some bottleneck detection tools are available that you can use. Here is the list of those tools:

  • SQL Profiler
    SQL Profiler is the tool with the ability to fetch and log the complete T-SQL activity of SQL Server. The default template can be used to capture the execution of SQL statement. In SQL 2005, SQL Profiler also allows users to add the blocked process report, usually found in the Errors and Warnings Events.
  • Dynamic Management Views (DMVs)
    A useful set of dynamic management views and functions are offered by SQL Server 2005. These views display the current SQL Server internal metadata and other events like server restarts and memory pressure. To avoid getting transitory events and have a meaningful result, use tables to save these views.

How to Fix SQL Server Performance Bottleneck

According to the SQL experts, certain steps can be taken to avoid bottleneck situations.

  • Keep Memory Under Supervision -If the available memory percentage drops below 20%, users will start encountering issues in performance. So it is necessary to always keep an eye on the memory usage. Review queries and identify the memory leaks for optimized performance of the SQL Server memory. Add more RAM to increase SQL Server scalability.
  • Find and Fix CPU Bottlenecks -To fix CPU bottleneck, find out the worst-performing queries that are giving your CPU a hard time. Then manage these queries and their underlying indexes. Using all available CPUs and adding faster CPUs can also resolve this problem.
  • Strict Monitoring of Disk I/O Usage -Storage I/O is the slowest of all SQL resources it should be always under observation for bottlenecks. If bottleneck symptoms are found, see if it is possible to attain better performance by improvising storage system design. The best techniques to solve I/O bottleneck situations is to introduce faster disks, distribute the load across different spindles and defragment the disk.
  • Well Structured Database Design -Any highly normalized database often causes long-running queries that squander resources like CPU and memory. Therefore, poor database design has to be avoided. For example, if any operation needs five or more table joins, the database should be redesigned.
  • Proper Index Management -Too many indexes make SQL Server work slowly by making it take more time to update. Duplicate and unnecessary indexes only drain system resources like CPU and I/O. Use SQL Server DMV or Database Engine Tuning Advisor (DTA) to determine the unused indexes.

Final Words

The above discussion answers how to find SQL Server performance bottlenecks. We have also focused on the symptoms and method to avoid SQL performance bottlenecks. Users will get definitely get benefited from this blog if they follow the instructions.

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