Improve Performance of SQL Query Like an Expert

by Tosska Technologies sql server performance tuning- Tosska Technologies

The simple syntax of the SQL language makes it easy to learn. One only needs to follow a set of commands to manage even the complicated databases. However, the trick does not always work. Sometimes two queries may look similar but vary with regard to computation time. This is why experts recommend fine-tuning SQL queries.


Whether you are a growing business or an already established organization that relies heavily on databases, optimization of SQL is essential. It reduces the need for manual performance tuning and allows you to prevent unwanted burdens. In this article, we have listed some of the best ways to ways to improve performance of SQL query.


 Determine your requirements before performance tuning a query. If you’re not sure how to do that, just follow the basic 5Ws rule - What, Where, When, Who, and Why? After answering these questions, specify the requirements and divide them into different priorities. Work on the highest priorities and then move to the least priorities.


 Indexes play a major role in ensuring hassle-free database access during vital times. But indexing isn’t an easy task, it is extremely challenging for those with limited experience. Novices tend to follow commands that either index everything or nothing at all. And when no indexing is done, the queries automatically start running slowly and put additional load on the database. Indexing everything also makes the database unproductive. Maintaining a balance is what works the best, so aim towards that.

   Make the right use of temporary tables. It is important to know that they can give rise to the complexities of a query. Experts prohibit novices from using temporary able as their codes are simply written. If you are, however, stuck in a situation where you have to use them, just seek help from an experienced professional.


  Even the most well-known DBAs suggest beginners avoid the use of SELECT* (Select All). It is an effective method for smaller tables but for bigger tables with numerous fields and rows, SELECT* isn’t fruitful. It burdens the resources and makes things all the more complex for them. Defining the fields in the SELECT statement for instructing the database to query only essential data is the best way to meet your objectives.


  Avoiding the use of COUNT () can also help you significantly improve performance of SQL query. There are various online tutorials that ask beginners to use COUNT() in the place of EXISTS(). It scans the table and counts queries that fit with the specified condition. EXISTS() on the other hand is highly efficient as it exists the loop right after spotting the desired result. It ensures improved functionings and helps to ensure a cleaner code.

  Beginners are advised not to use wildcard characters at the start of the LIKE pattern for optimization in SQL.

  To keep the database protected, it is essential for you to schedule some queries to off-peak hours, especially when the number of active users are the lowest. Choose less active hours such as 3 am to 5 am for running the following queries:

        Looping statements

        Nested subqueries

        Wildcard searches

        CROSS JOINs



Regular optimization in SQL is essential to improve performance of SQL query. However, the performance of a database depends on multiple factors. These include the type of information, database model, etc. For additional information on the same, simply consult professional DBA. They will be able to guide you better and won’t let you make the mistakes they did when they were starting out. 

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About Tosska Technologies Advanced   sql server performance tuning- Tosska Technologies

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Created on Jul 20th 2021 07:47. Viewed 114 times.


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