Hi @Azure_Data_Bric , As you mentioned you are not seeing the deleted records, my understanding of the issue is that new data has been loaded in the table since the day the historical data was deleted. It also suggests to me that you are not performing delete operations after that day.

If this is the situation, then the only space we can free up(using vacuum operation) is the space taken up by stale files. Please note that when you deleted the historical data and ran the vacuum, a large amount of space was released because you had deleted lot of the data. 

In addition to this, we can also look for below 2 problems:

1. Over partitioning: If your table is over partitioned, then the optimize will not be able to generate a lot of stale files which the vacuum command clears later.

2. Look for any problem at the cloud provider side if the vacuum is actually deleting the data or not. Or is it facing any issue there.