Size of Column store index on Table I copied a row-based table with about 90 million rows into a column store index Table. 

The decrease rate of the table was acceptable. But I want the size of column store index.

The sp_spaceused procedure didn't give any result for the column-based table. How can we get the size of the index?
With a clustered columnstore index, the data and index are one and the same so the reported data size includes both data and index.

A traditional b-tree clustered index also has non-leaf index pages which is reported separately by the index space.