Appending data when using Connector with Sql Query

Hi, have a quick question about a Workbench module on our Historian server. I'm running a query automatically every evening to update my Domo Dashboard (USCB Alarm Management Dashboard) with the data from the previous day. I'm querying the previous 24 hours. I'm appending the dataset.

My question is a foundational one related to the appending. I want to ensure I'm not adding data to the the dataset that already exists. I've attached my query and configurations here.

Thanks,

John Whited