SET NOCOUNT ON usage
The Great Debate: SET NOCOUNT ON for SQL Server - Yay or Nay?
š¤ Should we use SET NOCOUNT ON for SQL Server? If not, why not? This question has been circulating among SQL Server developers, and there seems to be differing views on the matter. Let's dive into this topic and explore the arguments on both sides.
š” What does SET NOCOUNT ON do?
SET NOCOUNT ON is a statement in SQL Server that suppresses the "xx rows affected" message after any DML (Data Manipulation Language) operation. The result set of this message needs to be processed by the client, which can have a small but measurable impact on performance.
For triggers and stored procedures, multiple "xx rows affected" messages can cause issues with certain ORMs (Object-Relational Mappers) like MS Access and JPA (Java Persistence API). This can lead to errors and unexpected behavior in the application.
š¼ The Accepted Best Practice
Until this question came up, it was generally accepted as best practice to use SET NOCOUNT ON in triggers and stored procedures. A quick Google search reveals that many SQL Server MVPs (Most Valuable Professionals) also endorse this practice.
However, MSDN warns that using SET NOCOUNT ON can break .NET SQLDataAdaptor. This limitation means that the SQLDataAdapter expects the "n rows affected" message to match, limiting certain advanced processing scenarios.
š« The Case Against SET NOCOUNT ON
Some developers, including the knowledgeable marc_s, advocate against using SET NOCOUNT ON. They argue that assuming internal processing of stored procedures works in a specific way can be considered bad form or an anti-pattern. Different clients with different SQL-related technologies, like C# SQLDataAdaptor and nHibernate from Java, can be affected differently by SET NOCOUNT ON.
Additionally, there are several documented cases where SET NOCOUNT ON causes problems with other technologies, such as triggers in nHibernate and JPA. The caveat is that these issues are not universal and may depend on specific configurations and use cases.
š¤·āāļø What Do You Think?
Now that you have the context, it's time to share your thoughts! Have you encountered any issues or noticed performance differences with SET NOCOUNT ON? Do you prefer using it or avoiding it altogether? We'd love to hear your experiences and insights on this matter.
Share your thoughts in the comments below and let's start a discussion! š¬
š Further Reading and Resources
Microsoft Support Article: KB 240882 - Issue causing disconnects on SQL 2000 and earlier.
Demo of performance gain - Demonstrating the performance difference with SET NOCOUNT ON.
Stack Overflow: Does SET NOCOUNT ON really make that much of a performance difference - In-depth details from Remus Rusanu about performance impact.
Remember, the goal is not to settle this debate once and for all but to understand the different perspectives and learn from each other's experiences. Let's keep the conversation going!
