Can anyone help me with this MCQ from Relational Algebra?
Comfort Shoe Supplier Database: CUSTOMERS (cust_no, cust_name, street, town, post_code, cr_limit, curr_bal) PRODUCTS (prod_cod, description, prod_group, list_price, qty_on_hand, remake_level, remake_qty) ORDERS (order no, order_date, cust_no) ORDER_DETAILS (order_no, prod_cod, order_qty, order_price) Some attributes, such as cust_name, are self-explanatory; however, others need some definition: cr_limit: The maximum that a customer is allowed to owe curr_bal: The amount currently owed by the customer list_price: The advertised price for a single unit of a particular product remake_level: The level to which the quantity on hand is compared; if qty_on_hand falls below this level, then the Nikke shoe supplier company will usually make another batch (to the manufacturer) to avoid stockout. remake_qty: The quantity usually made in any new batch. order_price: The unit price charged on this order for this product order_date: The date on which the order was taken. CUSTOMERS Custno Cust_name Street Town 1066 Bundy Shoe Kings St Bundoora 13144 Target High St Clayton 1776 Harry Store Elphin Rd Hawthorn Kmart Burke Rd Kew 2002 Oshoe Glen Rd Kew Post_code 3083 3800 3122 3101 3101 Cr limit 500 3000 500 500 1000 Curr_bal 450 1000 500 0 300 2001 PRODUCTS Prod_cod Description Prod_group List Qty_on_Remake_level price hand M09 Male Runner Male Shoes 150 6 3 LO9 Lady Runner Female Shoes 250 1 1 ST1 Girls Runner Female Shoes 300 10 5 LT1 Tennis Shoe General 450 1 2 LT9 Tennis Shoe General 100 20 15 GNO Beach Sandal General 10 100 150 ST2 Slipper General 50 50 35 GA2 Soccer Shoe Male Shoes 500 10 15 Nu Remake qty 5 3 15 2 20 200 20 40 ORDERS Order_no 0001 0002 0003 Order_date 01/07/93 02/07/93 02/07/93 Cust no 13144 13144 1066 ORDER DETAILS Order no Prod cod 0001 STI 0001 GA2 0002 ST1 0003 GN9 Order_qty 10 2 5 10 Order price 45 480 45 10 4.1 [7] With reference to the Comfort Shoe Supplier database, the relational algebra query as given below will result in the relation post_code = 3101 (cr_limit > 500 (CUSTOMERS)) A. Cust_no Cust_name Street Town Post_code Cr_limit Curr bal 2001 Kmart Burke Rd Kew 3101 2002 Qshoe Glen Rd Kew 3101 1000 500 0 300 B. Cust_no Cust_name 2002 Qshoe Street Glen Rd Town Kew Postcode 3101 Cr_limit 1000 Curr_bal 300 C. Cust_no 13144 2001 2002 Cust_name Target Kmart Qshoe Street High St Burke Rd Glen Rd Town Clayton Kew Kew Post_code 3800 3101 3101 Cr limit 3000 500 1000 Curr bal 1000 0 300 D. Cust no 13144 2002 Cust name Target Qshoe Street High St Glen Rd Town Clayton Kew Post code 3800 3101 Cr limit 3000 1000 Curr bal 1000 300 E. Post_code Cr_limit 3101 500 3101 1000
