You'll find INSERT SELECT UNION ALL interesting when you want to insert rows fro...

politician on Nov 24, 2015 | parent | context | favorite | on: Modern SQL: With – Organize Complex Queries

You'll find INSERT SELECT UNION ALL interesting when you want to insert rows from multiple table sources. For example, when refactoring a two tables into a single table or loading data into a temporary table (BCP) before copying it into a target table.