You have a customer table called CUST containing:

CustID $($primary key$)$

CustName $($the name of the customer$)$

CustPhone $($the phone number of the customer$)$

CustCreditLimit $($the amount of money that customer could owe$)$

You have a product table called PRODUCT containing:

ProdlD $($primary$)$

ProdName $($name of the product$)$

ProdDesc $($a long description of the product which may be over $10$ lines$)$

ListPrice

You have a payment table called PAYMENT containing:

PaylD $($each payment has a unique number $-$ primary key$)$

PayDate

CustID $($should match CUSTID in the CUST table$)$

PayAmt $($amount of money paid is US dollars$)$

You have a purchase table called PURCHASE containing:

PurchaselD $($each purchase has only one item and has a unique purchase number $-$ primary key$)$

PurchaseDate

CustiD $($should match the CUST table$)$

ProdID $($should match the PRODUCT table$)$

ProductPrice $($can include pennies$)$

Quantity $($must be a positive integer between $1$ and $99)$

a$.$ Look at the tables from part $(1).$ You wanted to delete product $123$ from the PRODUCT table. What effect will this have on any other tables and$/$or the purchasing history of each customer.

b$.$ You just executed a transaction which updated two records. Unfortunately, you now want to undo the effects of the transaction. What does the DBMS have to do in order to undo the effects of this transaction? $($Hint: there are several cases to consider.$)$ Be careful.