I have an Access query linked to 3 Oracle tables with some inner joins & filters. It runs fine in 10-15 seconds.

If I then make the query "unique values" on the 2 columns output, it never completes - the progress bar does not move.

If instead, I use "GroupBy" on one columns, and Max on the other, it also never completes.

If I nest 2 queries (inner one is the one that runs fine & returns 2 columns), and outter one asks for UniqueValues, again, it never completes.

If I turn the query that runs fine into a MakeTable query, the progress bar completes, BUT, it never finishes and does not "make a table."

What is going on? Can anyone help? I am not a guru at this, just a hacker in finance.