Database Software

While I was reading about "smart scan" in Exadata I noticed a mention that while processing a query, only the columns needed by the query are actually returned from the storage server to the database server.

Just wondering how this is achieved- I know that Exadata is not a columnar database and stores the data as rows in tabular format in the disk. Given this, does the storage software retrieve the full row (all columns), discards the unwanted columns and returns the rest to the database? Is this how this is achieved?

I'm evaluating a columnar database and wanted to see how Exadata was able to offer the same benefit of a columnar database but with row storage in the disks.