I have gone through some MSDN links which says space required for an index rebuild would be 120%- 200% but i was testing on one of the large table 100GB with a clustered index.
I shrink the DB & log file so it doesn't have free space and ran the stmt rebuild Index with tempDB off for the Clustered index, what i have seen is rebuild completed and when i claculated the free space it was just couple of GB in Data file and 1 GB on log file.
Why the Rebuild operation is not taking huge space as per documentation is it because of less fragmentation or the formula 120% to 200% gets applied for some kind of indexes?