How to Improve SQL Query Performance with Simple Things in Mind?

by Tosska Technologies sql server performance tuning- Tosska Technologies

SQL, an abbreviation of Structured Query Language is a standard language for relational database management systems (RDBMS). Typically, the language is used by developers, data analysts, and database managers. SQL statements are used to retrieve relevant data from any database that exists. For maximum performance, you should use the queries that are efficient along with being faster. Hence, you must have a SQL query performance tuning that is based on the business requirements.

Performance plays an important role in any application for running effectively. So, you should have a good database design that performs quite well during data manipulation. It is so because users always seek a fast response to the data retrieval action. There aren’t any silver bullets to performance tuning as it is not that easy. However, we can go a long way with a few basic tips on improving performance.

The first thing you need to ensure to improve SQL query performance is to generate an Actual Execution Plan. Doing so, you can easily diagnose slow queries.

Secondly, always try to prefix object names such as stored procedure name, table name, etc. with its schema/owner name. In case you don’t provide it, SQL Server’s engine will try to get it in all schemas until the object discovers it. However, when you provide the name, the server engine won’t search for the table outside of its schema/owner.

Besides, you should avoid the use of SELECT* (read as Select all) because it scans all the rows and fields in the table and presents a list of data in front of you. In turn, it becomes difficult to shorthand the data that you actually need. Instead, you should make the habit of using a SELECT statement. It will query only the required data from the table; and hence, makes the search faster and enhances SQL query performance.

Furthermore, you should also avoid using cursors. Basically, a cursor is a set of rows that along with a pointer identifies a current row. It’s working include retrieving data from a result set one row at a time. In turn, this makes the data fetching processing quite time-consuming. Instead, make use of a temporary table wisely; especially when you have to deal with a stored procedure that you can’t manage with a single query.

Use derived tables, temporary tables, or CTEs (Common Table Expressions) instead of using table variables in joins. Undoubtedly, even table variables are very fast and efficient in various situations and the server assumes it as a single row. Because of this reason, when they are used in joins, they perform quite horribly. Derived tables and CTEs perform better with joins when compared to table variables.

Apart from these techniques, there are a few other tips that you must consider for improving the SQL query performance. Some of them include avoiding the use of GROUP BY, ORDER BY, and DISTINCT, using SET NOCOUNT ON instead of using other statements that return affected rows, and more.

If you are an organization and don’t have a team of developers or DBA for SQL performance tuning, then you can contact Tosska Technologies. We provide products that will help you performance tune your database or SQL server without touching the actual code. Therefore, if you are seeking any such company than can truly help you with the performance tuning, connect with us soon.