Background: I'm in the process of optimizing a Data Warehouse style query with big dimension tables. The optimizer does not like to pick the typical star schema join plan at the moment. When I force this plan (by using an index hint) I can see that this star join plan is just a little more expensive than the plan I'm using right now. I suspect that is because the dimensions do not fit into RAM on my development machine. The version is SQL Server 2014 but I hope that the question can be generalized to all recent versions.
Question: Is there a way to make the optimizer believe that it has a lot of RAM at its disposal? For testing purposes I would like to obtain the plan that it would generate if it had 1TB of RAM available (instead of 8GB at the moment).