Database Reference
In-Depth Information
6.5.3 Case 3: In the UPDATE Operation
The entity integrity, the foreign key integrity, and the referential
integrity properties should be satisfied in the UPDATE operation.
Polyinstantiation integrity is satisfied because of the following:
• There is no polyinstantiated tuple
t
′ in the original relation
instance r with
tE At EA
′
[
(
)]
=
[
(
)]
∧
t
′[
TC
] >
L
∧
t
′[
C
i
] =
C
1
C
1
1
1
L(2 ≤
i
≤
n
).
• There is no polyinstantiated tuple
t
″ with
t
″
[
EA
(
)]
=
C
1
tE A
C
∧
t
″[
TC
] >
L
∧
t
″[
C
i
] =
L
(2 ≤
i
≤
n
).
Data-borrow integrity is satisfied because of the following:
[
(
)]
1
1
• There is no polyinstantiated tuple
t
′ in the original relation
instance r with
∧
t
′[
TC
] >
L
∧
t
′[
C
i
] =
tE At EA
′
[
(
)]
=
[
(
)]
C
1
C
1
1
1
L
(2 ≤
i
≤
n
).
6.5.4 Case 4: In the UPLEVEL Operation
The polyinstantiation integrity, the foreign key integrity, and the refer-
ential integrity properties should be satisfied in the UPDATE operation.
Entity integrity is satisfied because of the following:
• There is no tuple polyinstantiated tuple
t
′ in the original
relation instance r with
[
′ =
.
Data-borrow integrity is satisfied because of the following:
tE At EA
(
)]
[
(
)]
C
1
C
1
1
1
• There is no polyinstantiated tuple
t
′ in the original relation
instance r with
[
∧
t
′[
TC
] >
L
∧
t
′[
C
i
] =
tE At EA
′
(
)]
=
[
(
)]
C
1
C
1
1
1
L
(2 ≤
i
≤
n
).
6.6 Completeness
The completeness of the encryption-based multilevel database model
will be proven in this section. The following definitions will clarify
the meaning of the completeness in the encryption-based multilevel
database model [83].
Definition 6.6.1: If the sequences of the data manipulation operations
transform any legal database state to another legal database state, the
multilevel relational database will be complete.
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