SQL Server connection string Asynchronous Processing=true
Begining with .NET Framework 4.5, Asynchronous Processing property is ignored, thus it's unnecessary to include it.
Quote:
Prior to .NET Framework 4.5, asynchronous programming with SqlClient was done with the following methods and the Asynchronous Processing=true connection property:
- System.Data.SqlClient.SqlCommand.BeginExecuteNonQuery
- System.Data.SqlClient.SqlCommand.BeginExecuteReader
- System.Data.SqlClient.SqlCommand.BeginExecuteReader
This functionality remains in SqlClient in .NET Framework 4.5.
Beginning in the .NET Framework 4.5, these methods no longer require Asynchronous Processing=true in the connection string.
For more information, refer to below links:
As a matter of fact, there are performance issues when you enable that option; see the ADO.NET 2.0 Asynchronous Command Execution (ASYNC) FAQ:
Q: What is the new ADO.NET 2.0 Asynchronous Command Execution feature.
A: ASYNC allows you to execute a command in a non-blocking manner. We are exposing in the SqlCommand the following asynchronous methods: BeginExecuteNonQuery, BeginExecuteReader and BeginExecuteXmlReader with polling, synchronization and (shudder) callbacks.Q: So does this mean that every command I execute (sync or async) will happen in overlapped mode when I add ASYNC=TRUE to the connection string?
A: Yes it does, everything that we execute on this connection will be done in overlapped mode. For synchronous operations we internally wait for the completion before returning, we are basically faking the synchronous behavior on this connection. This is the reason why we require a connection string keyword.Q: Does this have a perf impact?
A: Definitely, only use ASYNC=TRUE when you know that you are going to be using the async functionality.
Just having the Asynchronous Processing=True in your connection string just simply enables you to write asynchronous queries - I don't see how having that setting in your connection string should affect your performance, if you don't change anything else.
You will hopefully begin to see a positive effect on your performance when you start doing asynchronous processing of your database queries. But just specifying that one option shouldn't have any (positive or negative) impact on your app.
Marc