I think the risk of creating indexes prematurely is really that you will make assumptions about how your table is going to be queried that don't turn out to be correct, so you create indexes that you will never need, even if the table gets large.
That probably isn't the end of the world, but it can make it harder for others to understand what is going on in your database (indexes can also be a form of documentation) and could make your ORM code somewhat more complex.
The worst case scenario, I suppose, would be you create an index on a table that grows large
That probably isn't the end of the world, but it can make it harder for others to understand what is going on in your database (indexes can also be a form of documentation) and could make your ORM code somewhat more complex.
The worst case scenario, I suppose, would be you create an index on a table that grows large