Space Allocation on the Target System
All Teradata on AWS instances require enabling Fallback. If the source tables do not have Fallback enabled, they will be twice the size on the target system.
Teradata instances on AWS that use EBS storage have block-level compression enabled by default, while instances using local storage have block-level compression disabled by default. When using local storage, you might need more storage space on the source system if the source data is already using block-level compression.
Reserve at least 30% space for spool space use for query processing.