how can I check that (deduped), and I dont understand the logic of querying on _id, could you please eloberate.

less than a week.

I have created a new schema, and a new dataset (Event) corresponding to it , both are profile enabled .Created a new dataflow from the source and it is a backfill enabled.Problem: I have ran a query to check the number of records in the dataset I got a count 'A'(2870051), but in the UI the count of ...