I'm looking for the most efficient way of getting an exclusive dataset.
I have circa 3m invoices in a table each with a client ID, and I have a list of 10k client IDs. I want the invoices that do not relate to the client IDs in the list.
For much smaller tasks I would do a 'WHERE ID NOT IN (SELECT ID FROM....)' etc. but I'm aware of this being a poor approach.
Thanks in advance.