问题
ServiceStack 3.9.69 via Nuget using SqlServer OrmLite dialect
I'm attempting to execute a parameterized stored procedure but am noticing an unusual slowness when the compilation mode is set to debug. The method that is slow is ConvertToList below:
Dim result = Db.Exec(Of List(Of Dto.FieldSample))(
Function(cmd)
cmd.CommandType = CommandType.StoredProcedure
cmd.CommandText = "up_GetFieldSample"
cmd.Parameters.Add(New SqlClient.SqlParameter("@uploadID", uploadId))
Dim reader = cmd.ExecuteReader()
Dim converted = reader.ConvertToList(Of Dto.FieldSample)()
Return converted
End Function)
(I know there is a .SqlList extension available, but I tried that first with the same results. I switched to Exec to get a better idea of where the issue was)
The stored procedure returns in 2-3 seconds when executed in non-debug mode, but 15-20 seconds in debug mode. I understand that there is often tracing, etc included in debug compilation but I'm trying to figure out what is actually so slow.
What is happening in debug compilation that is causing the query to take longer to execute?
回答1:
As I suspected, there is some internal error handling/logging being performed during ConvertToList when it calls PopulateWithSqlReader Source
The underlying issue was a data type mismatch between my POCO (decimal?) and the database (int). It wasn't until I hooked up a LogManager.LogFactory = New ConsoleLogFactory() that I could see that an exception was being thrown internally, logged, then moving on. The 235+ (rows) of exception handling was what was causing the delay.
来源：https://stackoverflow.com/questions/19611495/what-is-happening-in-debug-compilation-that-is-causing-the-query-to-take-longer