SQL Server Stored Procedure RPC VS SSMS

Question

I have a stored procedure that takes 1 parameter. When I run the stored procedure from SQL Server Management Studio, it runs in 2-4 seconds. When I call it with a console application, it takes 30+ seconds. The SQL Server is remote and both SSMS and my application are being run from my local machine so I don't think it's a networking issue.

I've ran the SQL Server Profiler to try to track down the issue and one thing I'm seeing is that when it's run from SSMS it starts the statement, recompiles it, then starts it over again, then completes it, like this:

SP:StmtStarting
SP:Recompile
SQL:StmtRecompile
SP:StmtStarting
SP:StmtCompleted

The 2 recompile entries have an EventSubClass of "2 - Statistics changed"

From the app I only see entries for SP:StmtStarting & SP:StmtCompleted, no recompile entries.

I'm calling exactly the same stored procedure with the same parameter value. Why does SSMS recompile based on statistics but my console app does not?

Answer 1

After researching and troubleshooting it appears to be entirely due to SET_ARITHABORT_ON. SSMS defaults this to 'ON' while the .net sql client defaults it to 'OFF' so it was going with 2 different execution plans, although I'm not entirely sure why the two plans are so drastically different.

I overrode the OpenConnection() method to open the connection set it to ON and my application then had the same performance as SSMS. I hope this helps anyone else who stumbles upon this.