Task 13: Write the command to display only tables within the system catalog that are of the type BASE TABLE. Display only the following columns: TABLE_SCHEMA, TABLE_NAME, TABLE_TYPE.

Task 14: Create an index named ITEM_INDEX1 on the ITEM_ID column in the INVOICE_LINE table

Task 15: Create an index named ITEM_INDEX2 on the CATEGORY column in the ITEM table.

Task 16: Create an index named ITEM_INDEX3 on the CATEGORY and LOCATION columns in the ITEM table.

Task 17: Create an index named ITEM_INDEX4 on the CATEGORY and LOCATION columns in the ITEM table. List categories in descending order.

Task 18: Delete the index named ITEM_INDEX3.

Task 19: List every table that you have created thus far. Display the TABLE_SCHEMA and TABLE_NAME columns.

Task 20: List every column in the ITEM table and its associated data type.

Task 21: Add the INVOICE_NUM column as a foreign key in the INVOICE_LINE table.