Question on cluster index creation and data file growth.

Hello,

Will creating a cluster index on a table of size 170 GB creates a copy of the whole table/column as it does during online re-indexing ? If a data file has additional 100 GB will it be sufficient. (to avoid auto grow) Any impact to log file ?

As per my understanding the data file needs only the space required to create index as it initially organizes the data  i.e index size ~100GB

So the total table size will be 170GB (DATA) + 100GB (INDEX)

I just want to understand how SQL handles the creation on cluster index.

Appreciate for any other valuable information.

Thanks