-- Mar 25 In-Class Exercise
Transaction Op |
Value s |
Memory Value A |
Disk Value A |
Value t |
Memory Value B |
Disk Value B |
Log Records |
|
|
|
|
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<START T> |
I(A) |
|
3 |
3 |
|
|
4 |
|
R(A,s) |
3 |
3 |
3 |
|
|
4 |
|
s:=s + 4 |
7 |
3 |
3 |
|
|
4 |
|
W(A,s) |
7 |
7 |
3 |
|
|
4 |
<T,A,3> |
FLUSH LOG |
7 |
7 |
3 |
|
|
4 |
|
I(B) |
7 |
7 |
3 |
|
4 |
4 |
|
R(B,t) |
7 |
7 |
3 |
4 |
4 |
4 |
|
t:= t*s |
7 |
7 |
3 |
28 |
4 |
4 |
|
W(B,t) |
7 |
7 |
3 |
28 |
28 |
4 |
<T,B,4> |
FLUSH LOG |
7 |
7 |
3 |
28 |
28 |
4 |
|
O(A) |
7 |
7 |
7 |
28 |
28 |
4 |
|
O(B) |
7 |
7 |
7 |
28 |
28 |
28 |
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<COMMIT T> |
(
Edited: 2020-03-25)
{|
|-
! Transaction Op !! Value s !! Memory Value A !! Disk Value A !! Value t !! Memory Value B !! Disk Value B !! Log Records
|-
| || || || || || || || <START T>
|-
| I(A) || || 3 || 3 || || || 4 ||
|-
| R(A,s) || 3 || 3 || 3 || || || 4 ||
|-
| s:=s + 4 || 7 || 3 || 3 || || || 4 ||
|-
| W(A,s) || 7 || 7 || 3 || || || 4 || <T,A,3>
|-
| FLUSH LOG || 7 || 7 || 3 || || || 4 ||
|-
| I(B) || 7 || 7 || 3 || || 4 || 4 ||
|-
| R(B,t) || 7 || 7 || 3 || 4 || 4 || 4 ||
|-
| t:= t*s || 7 || 7 || 3 || 28 || 4 || 4 ||
|-
| W(B,t) || 7 || 7 || 3 || 28 || 28 || 4 || <T,B,4>
|-
| FLUSH LOG || 7 || 7 || 3 || 28 || 28 || 4 ||
|-
| O(A) || 7 || 7 || 7 || 28 || 28 || 4 ||
|-
| O(B) || 7 || 7 || 7 || 28 || 28 || 28 ||
|-
| || || || || || || || <COMMIT T>
|}