From the DWHPro archive
Teradata ALTER Table vs. INSERT INTO: Which Method is Efficient?
ALTER TABLE or INSERT INTO a new table? A measured comparison on a large table, and which one actually used fewer resources.
Also worth reading: Teradata SQL Tuning and Query Rewriting
— Roland
Written by Roland Wenzlofsky — 25 years on enterprise data platforms, author of Teradata Query Performance Tuning.