Example – Skew Write
•MakeSale(p1,s1,26) MakeSale(p1,s2,25)
•Update row 1: 30->4
• update row 2:
35->10
• find sum: 72
• // No need to Insert row in Order
•Find sum: 71
•// No need to insert row in Order
•COMMIT
• COMMIT
etc
etc
etc
60
s1
p2
35
s2
p1
30
s1
p1
Initial
state of InStore, Product, Order
Final
state of InStore, Product, Order
Integrity constraint is
false:
Sum is 46
etc
etc
etc
60
s1
p2
10
s2
p1
4
s1
p1
etc
etc
etc
44
etc
p2
32
etc
p1
etc
etc
etc
44
etc
p2
32
etc
p1
Order:
empty
Order:
empty
NB: sum uses old value of
row1 and Product,
and self-changed value of
row2
