DMV [dm_pdw_exec_requests] having NULL start_time stamp, resource class

Question

I have a SQL Procedure running on SQL DW everyday and I was trying to analyze the stats that is captured in DMV [dm_pdw_exec_requests].

My Procedure ran for 288 minutes- but when i saw in DMV table , I see it has 10 rows with few rows having null resource class and empty start_time. Is it fair to exclude all rows with NULL/empty in start_time and resource_class to find the total time elapsed ?

Thanks, Aravind

Answer 1

If you query sys.dm_pdw_exec_requests, you should see a single entry for each batch execution. If you have a statement like this:

SELECT 1;
GO

SELECT 2;
GO

You would expect to see two rows in dm_pdw_exec_requests:

In your case, I'm assuming your procedure is the one with the command exec dbo.Proc1. You would only look for the total_elapsed_time for that statement. The other entries are other batches you have executed against your instance. We have a great write up on how to Monitor your workload using DMVs that will be very helpful.