How do I test structural changes in a large database?

2018-07-16 23:34:42

I have a couple large tables containing analytic data that are queried very often. I suspect restructuring the data into a star schema would improve the speed of the queries I need to execute.

How can I test how the new schema would affect query performance? It would be nice to test the changes in a local database, but it takes forever to copy the data. I'm dealing with roughly 1B rows across 2 tables.