1)
==========================

Atomicidade:

x.valor = 5
write(x)
FALHA
		read y
		commit
x.valor = 0
write(x)


Isolamento:
---------

x.valor = 5
		x.valor = 10
write(x)
		write(x)


Durabilidade:
---------

x = 5
		read y
		commit
write x
FALHA



2)
====================================
falha:
no undo / no redo
undo / no redo       
no undo / redo
undo / redo

buffer:
undo / redo		steal / not force
undo / no redo		steal / force
no undo / redo		not steal / not force
no undo / no redo	not steal / force



3)
=====================
Usando a técnica UNDO/REDO, o uso de FORCE torna-se redundante e desnecessário, já para se usar UNDO/NO-REDO é OBRIGATÓRIO o uso
do FORCE. 

4)
=======================


5)
========================
a)
x=5
write x
		read x
				read y
				commit

		x = x+4
		write x
		commit

x=10
write x
commit

b)
------------
x=5
write x
		read x
				read y
				commit

		x = x+4
		write x
		commit

x=10
write x
commit

c)
-----------------
NÃO É 2PL
lx x
write x
u x
		ls y
			ls z
		read y
			read z
			commit
		commit
lx y
write y
u y
c

d)
------------------
15:00		15:30		16:30

write x
		read x	
				write y
write y (abort)
		(abort)

-------------------

1		2		3

write x
		read x (wait)
commit
				read y
				commit
		(saiu wait)
		read x
		write x
		commit


1 -> 2 -> 3

-------------------

WTF?

------------------

lix bd
lix medicos
							lix bd
lx  dr linus
write dr linus
		lix bd
		lix medicos
		lx dr house
u dr linus
		lx dr linus (so pode depois do u)
		u dr linus
		u dr house
		u medicos
		u bd		
u medicos
							lx medicos(so pode depois do u)
u bd
							u medicos
							u bd