Final answer:
It is true that you are allowed to use column qualifiers on the columns that you use to join tables in a database. These qualifiers help to avoid ambiguity and ensure the SQL engine knows which table each column is coming from, especially when the joined tables contain columns with the same name.
Step-by-step explanation:
When joining tables in a database, you are allowed to use column qualifiers on the columns that you use to join the tables. This statement is true. Column qualifiers, often in the form of table aliases, are used to specify which column you are referring to when columns in different tables have the same name. This practice avoids ambiguity and ensures that the SQL engine knows precisely from which table to pull each column.
For instance, if you have two tables, Customers and Orders, and both tables have a column named 'Customer ID', when joining these tables, you need to qualify the column name with the table name (e.g., Customers. Customer ID = Orders. Customer ID), so the database knows you intend to match the Customer ID from the Customers table with the Customer ID in the Orders table.