Fixing SQL Server Database Performance Issues

Andrew Jackson | July 16th, 2016 | SQL

Overview

Most of the common issues encountered by the user of SQL Server database are degradation of performance, which has negative impact on the working of the SQL database. It is necessary to monitor both the hardware and software parameters in order to prevent any SQL Database performance issues. The foremost thing that user needs to do after facing any performance issues is to find the possible cause to understand the issue better. Some of the issues can be easily resolved while other issues may take time to resolve. In the article, we will be discussing about SQL Database Performance Issues and the causes that led to occurrence of these issues.

How to Detect the Database Performance Issues In SQL Server ?

Before resolving the issues, user needs to know the symptoms first. Some of the common issues are associated to CPU, memory, network and I/O bottlenecks and slow SQL queries.

Let us understand each of issues in depth:

Problem Related to CPU

The insufficient hardware resources can lead to problem in CPU. User need to identify the SQL Server Instance who is consuming most of the CPU. Occasional high usage of processor cannot be treated as serious issue and can be ignored. However, if the issue appears very often, investigation over the issue is needed. In this situation, adding extra processors may not be helpful. Therefore, solution is set proper query tuning, improve the execution plan and reconfigure the system to resolve the issue. It is advisable to keep a dedicated server to run the SQL Server only and no other applications should be present.

Memory Issues

It can lead to decrease in response times in the application, which will lead to overall slowdown of the system or even crash of the system. It is advisable that user checks when the system is having less memory space or which applications use most of the storage. To resolve this, user can provide more physical memory space; change the memory configuration, etc.

Network Associated Problem

The issue cannot be detected easily and often user considers it as the problem related to other resource. If there is a delay of data sent over network, it will lead to slower SQL Server response.

Issue in Input/output

High rate of reading from the disk and writing pages into the disk may lead to I/O issues. If some applications are consuming all the resources, SQL Server may lack enough disk resources for its working and would have to wait for long time.

Slow Running SQL Queries

It can be occurred due to missing or lost indexes, weak execution plans and badly designed schema, etc.

Reasons for SQL Server Database slow Performance

There may be several causes for the occurrence of issues related to SQL Database performance. Some are the common causes are poorly designed database, improper configuration, insufficient Disk Space, excessive Query Compilation, bad Execution Plans, queries taking long time, etc.

  • Memory issues can be caused by less memory storage and high consumption of memory by SQL Server instances. Improper indexing requires scanning of the SQL Server database table as large number of rows means large table. It needs to be read from disk and the queries will take time to execute.
  • If the database structure is not well defined, it may lead to slower performance. The database tables needs to be properly normalized and if not, problem may arise.
  • If the SQL query is well formed or optimized, it can give better performance. SQL construct can be chosen as per the requirement like in case of GROUP BY command, people are seen to be using WHERE and are complaining for slow response times.
  • Database Compiler needs to process the SQL query, which involves tasks like parsing, optimizing, identifying the query. In small applications, same query is executed several times. Therefore, Usage of bind variable can be helpful for storing the compiled query once used and execute it with different data at several times.
  • Stored procedures provides a good way for performing complex computations as they are already compiled and it requires less network for the result as compared to SQL queries.

Conclusion

Slow performance may hinder the working of the SQL Server database and may have negative impact to the growth of the organization. In the article, we have thoroughly understood the SQL Database Performance Issues. It further describes the ways to detect the issue or symptoms along with the possible causes related to slower SQL database performance issues.