Resolve T-SQL Performance Issues In SQL Server

Stephen West ~ Modified: January 30th, 2019 ~ SQL Transaction Log ~ 4 Minutes Reading


There could be various factors which can result in poor performance of the database.Troubleshooting the problems of the database is not an easy task as there are so many factors which need to check every time. These factors result in maintaining the performance of SQL Server. There are various components which result in degraded performance of SQL Server and cause bottleneck.
Executing bad T-SQL command is one of the root cause of degraded server performance as the core database logic uses T-SQL statements. Here, I will discuss, how can you avoid SQL Server database bottlenecks and give you some tips to resolve performance issue in SQL Server.

Tips to Resolve Performance Issue in SQL Server

1. Neglect UNION and DISTINCT Clauses

Try to avoid DISTINCT and UNION operators in T-SQL code, whenever possible.They can badly impact the performance of query execution as it is necessary to perform sorting operations to recognize and eliminate duplicate records from the query result set.

2. Use Column_list to Troubleshoot Performance Problem in SQL Server

It is not necessary for the INSERT and SELECT statements to use column_list parameters. But it is a good idea to give a full-column list for these SQL Server statements.If you are not using the column_list parameter in SELECT and INSERT operation, it may generate error related to the schema of table. So it is better to use the column name in the SELECT statement to decrease network traffic and increase the whole performance of the SELECT query.

3. Use Stored Procedure

Use stored procedures instead of T-SQL patches as code inside a stored procedure is accomplished either as a batch or single unit.

This decreases the network traffic since there are so many T-SQL statements contained in the stored procedure that do not travel through separate networks. Only the parameters and the name of the stored procedure can communicate over the network.

SQL server maintains an area of memory call procedure cache to reserve a stored procedure execution plan. Provided there is sufficient memory available, the stored procedure is not accomplished with the WITH RECOMPILE option. The stored procedure can be reused and remain in the procedure cache. The Ad hoc SQL plans built when the running Ad hoc T-SQL queries are not always provided in the procedure cache.

4. Use Truncate Table in Place of DELETE Statement

Instead of DELETE statement, try to make use of TRUNCATE statement. When clearing all the records from a table, the TRUNCATE statement quickly deletes all records in the table and is faster than the DELETE command without using the WHERE clause because it doesn’t store the transaction logs resource. Even the Truncate table doesn’t impact the table structure. The truncate statement doesn’t allocate the pages. But the DELETE statement keep logs for every deleted record so the process takes time to complete the task.

5. Maintain Small Transaction

Running numerous large transactions at the same time increases the probability of a deadlock, so maintain the transactions as small as possible. For faster execution, manipulate large transactions into smaller one and then run these transactions in batches. This may reduce the deadlock and minimize the network round trips at the time of transaction.

Making small transactions reduces the transaction time which is required for large transaction and enhance the performance of the Server by reducing its load factor.

6. Select the Right Data Types

Data types in SQL Server declare that what kind of data can be inserted in a database table column. When creating a new table it is necessary to choose the appropriate data type for the column. The data types can also be used to define variables, output parameters and stored procedure inputs. For every variable and column select a suitable data type to store the data in it. Selecting the appropriate data type for tables, stored procedures improve the integrity of data and confirm that only accurate type of data is stored in the database.


The above blog describes how the performance of SQL Server, depends on major factors like T-SQL commands and the data types responsible for maintaining data integrity of the database. The SQL Server performance fails when the T-SQL performance problems occur. It also covers how transaction log plays a major role in SQL Server working and how to resolve  performance issue in SQL Server.