Consider a bank database with only one relation
transaction (transno, acctno, date, amount)
The amount attribute value is positive for deposits and negative for withdrawals.
- Define an SQL view TP containing the information
for every pair of transaction T1,T2 and such that T1 and T2 are transaction on the same account and the date of T2 is $\leq $ the date of T1.
- Using only the above view TP, write a query to find for each account the minimum balance it ever reached (not including the 0 balance when the account is created). Assume there is at most one transaction per day on each account and each account has at least one transaction since it was created. To simplify your query, break it up into 2 steps by defining an intermediate view V.