Allowed Column Alteration in Non-Modifying Data Mode

Why it matters

This feature enables users to perform ALTER COLUMN operations without modifying underlying data if the column type remains unchanged, improving efficiency and flexibility when managing table schemas.

How to use it

Use the ALTER TABLE statement with the MODIFY COLUMN clause specifying the same column type. The operation will be allowed in non-modifying data mode, avoiding data rewriting. For example:

ALTER TABLE table_name MODIFY COLUMN column_name column_type;