Multimedia Database
Schema Design
Jianguo Huo
Outline
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MMDB Design Issues
Multimedia Data Types
Features and Similarity Functions
M-Dependencies
Normalization
Evaluation
MMDB Design Issues
• Requirements for the MMDB
– Representation, storage, interpretation,
composition, retrieval and delivery of diverse
data types
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Data Model
Storage structure
Architecture
Retrieval algorithms
MMDB Schema Design
• Building blocks
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Data type
Relations
Rows (tuples)
Columns
Similarity function and thresholds
Dependencies
MMDB schema
• Knobs
– Data types, relations, similarity functions, thresholds
Data Types
• Semantics of Multimedia Attributes
• Why not BLOB
• Generalized Icon
– (xm, xi)
– Earcons, ticons, micon, vicons
– multicons
Features and Similarity Functions
• Features and Tuples comparison
– Equal vs. similar
• Similarity Functions
– Distance functions
– Threshold
– Combination of similarity functions
Let R(z1:Z1,…, zn:Zn), v be a tuple distance function on R, t be a maximum
distance threshold, x=(x1,…, xn) and y=(y1,…, yn) be two tuples in R,
we say that x is similar within t to y with respect to v, denoted with x w(t) y,
iff v(x, y) t.
M-Dependencies
MFD: Let R be a relation with attribute set U, and X, Y  U. Xg1(t’) → Yg2(t’’) is a
type-M functional dependency (MFD) relation if and only if for any two tuples t1 and t2
in R that have t1[X] g1(t’) t2[X], then t1[Y] g2(t’’) t2[Y], where g1TD(X) and g2TD(Y),
whereas t’ and t’’  [0,1] are thresholds.
• The benefits from exploiting dependencies
• Classes of M-Dependencies
MMD: Let R be a multimedia relation with attribute set U, and X, Y  U. Xg1(t') →»
– Type
M Functional
dependency
(MFD)
Yg2(t'')[g3(t''')]
is a type-M
multivalued dependency
(MMD) relation
if and only if for any
two tuples t1 and t2 in R such that t1[X] g1(t') t2[X], there also exist in R two tuples t3
– the
Type
M Multivalued
dependency (MMD)
and t4 with
following
properties:
t3[X], t4[X]  [t1[X]]g1(t')
– Type
Mt4[Y]
Join
dependency
(MJD)
t3[Y] g2(t'')
t1[Y] and
g2(t'')
t2[Y]
t3[R– (XY)] g3(t''') t2[R – (XY)] and t4[R – (XY)] g3(t''') t1[R – (XY)].
– …technically
where g1TD(X),
g2TD(Y) and g3TD(R–(XY)), whereas t', t'' and t'''  [0,1] are
thresholds.
MJD: Let R be a relation on U, and {X1,…,Xn}  U, with the union of Xi’s being U. If R =
PX1,g1(t1)(R) g1(t1) PX2,g2(t2)(R) g2(t2)…gn-1(tn-1) PXn,I (R), we say that R
satisfies a Type-M Join Dependency (MJD), denoted by [g1(t1),…, gn-1(tn-1)][X1,...,
Xn], where giTD(Xi  Xi+1) and ti  [0,1] for each 1  i  n-1.
Normal Forms
1MNF: We say that a multimedia database schema is in first multimedia normal form
(1MNF) if each attribute A has the type of number, string or elementary generalized icon.
• Dependency-based design practice
2MNF: We say that a multimedia database schema is in second multimedia normal form
• Benefits
(2MNF)
if it is in 1MNF and each non prime attribute A is fully dependent on the primary
key.
• Types of Normal Forms
3MNF: We say that a multimedia database schema R is in third multimedia normal form
1MNF
(3MNF) if–it is
in 2MNF and the non prime attributes are not mutually dependent.
4MNF: We
that a multimedia database schema R is in fourth multimedia normal
– say
2MNF
form (4MNF) with respect to a set of multimedia dependencies D if, for every nontrivial
– 3MNF
MMD Xg1(t1)
→» Yg2(t2)[g3(t3)] in D+, X is a superkey for R.
–say
4MNF
5MNF: we
that R is in 5MNF with respect to a set D of MFDs, MMDs, and MJDs if,
for every nontrivial type-M join dependency [g1(t1),…, gn-1(tn-1)](X1,..., Xn) in D+,
– 5MNF
every Xi is a superkey for R.
– …technically
Term Project:
MMDB Refactoring
Project Goal
• To implement an usable tool to enable
automatic database transformation
– Improve the user interface
– Improve the algorithm