Multimedia Database Schema Design

1. Multimedia Database Schema Design Jianguo Huo

2. Outline • MMDB Design Issues • Multimedia Data Types • Features and Similarity Functions • M-Dependencies • Normalization • Evaluation

3. MMDB Design Issues • Requirements for the MMDB • Representation, storage, interpretation, composition, retrieval and delivery of diverse data types • Data Model • Storage structure • Architecture • Retrieval algorithms

4. MMDB Schema Design • Building blocks • Data type • Relations • Rows (tuples) • Columns • Similarity function and thresholds • Dependencies • MMDB schema • Knobs • Data types, relations, similarity functions, thresholds

5. Data Types • Semantics of Multimedia Attributes • Why not BLOB • Generalized Icon • (xm, xi) • Earcons, ticons, micon, vicons • multicons

6. 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.

7. M-Dependencies MFD: Let R be a relation with attribute set U, and X, Y  U. Xg1(t’) → Yg2(t’’) is a type-Mfunctionaldependency (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 • Type M Functional dependency (MFD) • Type M Multivalued dependency (MMD) • Type M Join dependency (MJD) • …technically MMD: Let R be a multimedia relation with attribute set U, and X, Y  U. Xg1(t') →» Yg2(t'')[g3(t''')] is a type-Mmultivalued 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 and t4 with the following properties: t3[X], t4[X] [t1[X]]g1(t') t3[Y] g2(t'') t1[Y] and t4[Y] g2(t'') t2[Y] t3[R– (XY)] g3(t''') t2[R – (XY)] and t4[R – (XY)] g3(t''') t1[R – (XY)]. 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.

8. 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 • Benefits • Types of Normal Forms • 1MNF • 2MNF • 3MNF • 4MNF • 5MNF • …technically 2MNF: We say that a multimedia database schema is in second multimedia normal form (2MNF) if it is in 1MNF and each non prime attribute A is fully dependent on the primary key. 3MNF: We say that a multimedia database schema R is in third multimedia normal form (3MNF) if it is in 2MNF and the non prime attributes are not mutually dependent. 4MNF: We say that a multimedia database schema R is in fourth multimedia normal form (4MNF) with respect to a set of multimedia dependencies D if, for every nontrivial MMD Xg1(t1) →» Yg2(t2)[g3(t3)] in D+, X is a superkey for R. 5MNF: we say 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+, every Xi is a superkey for R.

9. Term Project: MMDB Refactoring

10. Project Goal • To implement an usable tool to enable automatic database transformation • Improve the user interface • Improve the algorithm