Hello, I would like to solve these questions today as text, please

Question 1

Consider a bank database with this partial schema: Branch(bNo, bAddress, Bphone) Customer(cID, name, phone, cAddress) Account(aNo, type, balance, bNo)

Customers Accounts(cID, aNo)

Apply the equivalence rules to generate an optimized final tree of this query: SELECT C.name, C.phone, A.aNo, A.balance

FROM Branch B, Customers Accounts CA, Account A, Customer C

WHERE A.balance > 10,000 AND B. bAddress = "Riyadh" AND C. phone > B.Bphone AND C.cAddress=B. bAddress AND B.bNo=A.bNo AND CA.aNo=A.aNo AND CA.cID=C.cID;

Note: the joins costs are CA on A = 100; 000 records, A on B = 150; 000 and C on CA = 95; 000 records.

Question 2

Consider the following schedule S, consisting of transactions T1, T2 and T3

T1	T2	T3
begin
	begin
		begin
		Write(A)
Read(A)
	Write(B)
		Write(B)
	Write(B)
		commit
Write(A)
	Read(B)
Read(B)
commit
	commit

• Draw the precedence graph of transactions to determine whether the schedule is conflict-serializable.

• For the same schedule determine if they are view serializable. If found be view serializable, give a corresponding serial schedule, if not view serializable provide a suitable justification.

Question 3

For the following schedule, determine the following:

1. Has a deadlock occurred in the schedule? Show the WFG.
2. Which transaction(s), if any, would abort using Wait-Die technique and when?
3. Which transaction(s), if any, would abort using Wound-Wait technique and when?

	T1	T2
t1	begin
t2		begin
t3		Lock-s(y)
t4		Read(y)
t5	Lock-X(x)
t6	Read(x)
t7	Write(x)
t8		Lock-S(x)
t9		Read(x)
t10	Lock-X(y)
t11	Read(y)
t12	Write(y)
t13		Commit/unlock (y,x)
t14	Commit/unlock (x,y)