using delta lake tables as lookups on another changing delta table

Question

I have a scenario where I'm using one delta table as a lookup table for another delta table. if during the lookup, a lookup value gets added to the underlying table during the operation, will it been picked up in my lookup join?

Answer 1

At the beginning of each job, Delta will select a snapshot of the table that will be used for the entire duration of the job. Delta will always select the latest snapshot available when the job starts, but if the table changes during the execution of the job it will not see those changes.