The ALTER TABLE.. ADD COLUMN statement adds a column to an existing table. This operation is online in TiDB, which means that neither reads or writes to the table are blocked by adding a column ...

To add, drop, or modify a column's definition or attributes, use the ALTER TABLE statement, described in ALTER TABLE Statement. In the SET clause, a column reference on the left side of the equal sign ...

Add a new column to the table; Update new column on converted value from the old column (I think Trino doesn't support update yet) Rename old column or drop the old column; Rename the new column to ...