Clarifications on Aggregates

Hi Experts,

I need some clarification on Aggregate functionality:

I have a InfoCube having old and new data.I have Aggregates build on new data and old data is compressed in InfoCube.

I dont want to build Aggregates for old data because of some reasons.

Now my question is, if i fire a query based on both old and new data, will it hit the

Aggregates (for new data) as well as InfoCube(for old data)

Only InfoCube.

Please clear this doubt.

Regards,

Ashish