Download - A Fuzzy Valid-Time Model for Relational Databases Within the Hibernate Framework

Contents

Motivation

Context

Proposal

Example

Comparison

Conclusions and . . .

Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

A Fuzzy Valid-Time Modelfor Relational DatabasesWithin the Hibernate

FrameworkJose Enrique Pons Olga Pons Capote

Ignacio Blanco MedinaDepartment of Computer Science and Artificial Intelligence

University of Granada, Spain{jpons,opc,iblanco}@decsai.ugr.es

October 22, 2011

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

1. Contents

The structure of the presentation is:

• Motivation.

• Context:

– Fuzzy relational databases.

– Temporal databases.

– Fuzzy temporal databases.

– Hibernate.

• Proposal: Fuzzy Valid-Time model for relationaldatabases.

• Conclusions and future work.

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

2. Motivation

• Time-related attributes are considered to havean impact on the consistency of the object setmodelled by the database.

• A true standard for fuzzy temporal databasesdoes not exist.

• General model to represent and querying fuzzytemporal types in any relational database.

• Portable implementation within the HibernateFramework.

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

3. Context

• 3.1 Fuzzy relational databases (FBD):

– Representation: fuzzy data types.

– Querying: flexible querying.

• 3.2 Temporal databases:

– Time models (valid-time, transaction time,decision time... )

– Temporal operators.

• 3.3 Fuzzy temporal databases:

– Fuzzy Validity Period.

• Hibernate.

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

3.1. Fuzzy relational databases

Two main features:

• Fuzzy representation”The restaurant X in the database is cheap inaverage.””The restaurant X in the database is a ham-burguer bar.”

• Flexible querying:”The user wants to obtain a list with cheaprestaurants.”

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

3.1.1. Fuzzy data types

Two main types:

• Ordered underlying domain:

1

016 18 24 26

possibility

Cheap Middle-price Expensive

Price

This data type may be represented as a trapezoidin the form: [α, β, γ, δ].E.g. Middle-price = [16, 18, 24, 26]

• Non-ordered underlying domain:Fast food Hamburger Chinese

Fast food 1 0.8 0.6Hamburger 0.8 1 0.2

Chinese 0.6 0.2 1

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

3.1.2. Flexible Querying

The user may query with vagueness in the database:”The user want to obtain a list of cheap restau-rants.”

ID Name AVG Quality001 Amadeus [15,10,20,5] 5002 Atlantis [11,5,17,6] 3003 Cafe Theatre [20,10,30,10] 2004 De Graslei [23,18,28,5] 5005 Pakhuis [13,11,15,2] 3006 De 3 Biggetjes [45,25,65,20] 4

1

016 18 24 26

possibility

Cheap Middle-price Expensive

Price

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

The selected restaurants are:

ID Name AVG Quality001 Amadeus [15,10,20,5] 5002 Atlantis [11,5,17,6] 3005 Pakhuis [13,11,15,2] 3

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

Operators for fuzzy querying:

Possibility Necessity Possibly / NecessarilyFEQ NFEQ Fuzzy =FGT NFGT Fuzzy >

FGEQ NFGEQ Fuzzy ≥FLT NFLT Fuzzy.<

FLEQ NFLEQ Fuzzy ≤MGT NMGT Much >MLT NMLT Much <

FEQ(p1, p2) = supd∈U

min(πp1(d), πp2(d)) (1)

Where U is the underlying domain, p1, p2 are twovalues of a given fuzzy type (e.g. fuzzy type 2) andπp1(d), πp2(d) are the associated possibility distribu-tions.

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

Context:









Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

3.2. Temporal Databases:

A temporal database is a database that manages thetime in its schema.Time-related attributes have an impact on the con-sistency of the database.

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

Example:

ID Name Year Works for Start Year End Year1 Peter 1987 John 2010 -2 Maria 1978 John 2001 -3 John 1954 - 1999 -4 Sarah 1982 Maria 2005 2009

Consider that ID is the primary key.Problem: If Sarah is hired in 2010, we can notinsert the new tuple.

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

Example:

New primary key:

{ ID ∪[ Start Year, End Year ]}

ID Name Year Works for Start Year End Year1 Peter 1987 John 2010 -2 Maria 1978 John 2001 -3 John 1954 - 1999 -4 Sarah 1982 Maria 2005 20094 Sarah 29 Maria 2010 -

Also a consistence mechanism must be defined...

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

Example:

Some spurious values might be inserted:

ID Name Year Works for Start Year End Year1 Peter 1987 John 2010 -2 Maria 1978 John 2001 -3 John 1954 - 1999 -4 Sarah 1982 Maria 2005 20094 Sarah 29 Maria 2001 20074 Sarah 1982 Maria 2010 -

Usually, DML sentences (insert, update, delete) arere-defined to ensure consistency.

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

3.2.1. Temporal models

• Valid-Time: The time when the fact is true inthe modelled reality.

• Transaction time: The time when the fact isstored in the database.

• Decision-time: The time when an event wasdecided to happen.

• Bi-temporal: Valid and transaction time.

• Tri-temporal: Valid, transaction and decisiontime.

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

3.2.2. Temporal operators:

Allen’s temporal relation between intervals:Operator Inverse RepresentationX Before Y After XXX YYY

X Equal Y Equal XXXY Y Y

X Meets Y Meet by XXXYYY

X Overlaps Y Overlap by XXXY Y Y

X During Y Contains XXXY Y Y Y Y Y

X Starts Y Start by XXXY Y Y Y Y Y

X Finishes Y Finished by XXXY Y Y Y Y Y

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

Context:









– Fuzzy temporal operators.

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

3.3. Fuzzy temporal databases:

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

3.3.1. Fuzzy Validity Period:

time

time

possibility

possibility

1

1

0

0

VST VETInitial data values

ds-as ds ds+bs de-ae de de+be

d1-a d1 d2 d2+b

S1

S2

α= β= γ= δ=

S1 = S2 ⇒(ds + bs)− (ds − as)

2=d1 − (d1 − a)

2(2)

Where d1 = ds + bs and d2 = de + ae.The FVP is [d1 − a, d1, d2, d2 + b].

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

Underlying domain: Julian Day Number (JDN): Acounter which value is incremented in one unit everyday since 1 January 4713 B.C noon.Reasons:

• Representation as unique number

• Simplification of calculations.

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

3.3.2. Fuzzy temporal operators:

• BEFORE (I,J) =

1, if Iβ ≤ Jα

Iα−Jβ(Jα−Jβ)−(Iβ−Iα)

, if Iβ > Jα and Iα < Jβ

0, otherwise (Iα ≥ Jβ)

• OVERLAPS (I, J) =

supt

(min (I (t) , J (t)))

• CONTAINS (I, J) =

inft{max (1− I (t) , J (t))}

• EQUALS (I, J) =

min (CONTAINS (I, J) , CONTAINS (J, I)) =

min(inft{max (1− I (t) , J (t))},

inft{max (1− J (t) , I (t))})

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

Fuzzy temporal operators implemented in FSQL:

Operator Name FSQL implementationBEFORE (I, J) I FGEQ JOVERLAPS (I, J) I FEQ JEQUALS (I, J) min(I NFEQ J, J NFEQ I)CONTAINS (I, J) I NFEQ J

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

3.4. Hibernate Framework

The Hibernate Framework is a collection of opensource projects that enable developers to makeobject-relational mapping. Features:

• Database independent by means of dialects.

• HQL: an object-oriented query language.

• Open source.

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

3.4.1. Architecture

An application working with Hibernate has 3 layers:

1. Application layer: CRUD (CReate,Updateand Delete) operations:

(a) Persistent Objects: A current database state.

(b) Transient Objects: These objects do not rep-resent a current database state.

2. Hibernate layer: An abstraction layer be-tween the DBMS and the application.

3. The database: The running DBMS: MySQL,PostgreSQL, Oracle...etc.

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

Hibernate Architecture:

HIBERNATE

XML mapping

Application

Persistent Objects

hibernate.

properties

Database

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

3.4.2. Querying in Hibernate

1. Query by criteria:createCriteria(Person.class).Add(Restrictions.eq(”login”,”lmmn”));

2. Query by example:Person p.login = ”lmmn”;

3. HQL:Select p from Personal p where p.login =”lmmn”;

4. SQL:Select * from Person as p where p.login =’lmmn’;

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

4. Proposal

• Architecture for the general framework for:

– Fuzzy representation.

– Fuzzy querying.

• Implementation within the Hibernate frame-work.

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

4.1. Fuzzy Representation

Conditions for portability:

1. The SQL standard is the interface.

2. The fuzzy types are represented in the databaseby basic SQL types.

3. The meta-data for managing properly the ex-tended types relies outside the database catalog.

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

4.1.1. Architecture for the general model

The architecture for a generalized object-orientedmodel needs the following elements:

Object-Oriented Layer.

(OORL)

MySQL

Object-Oriented to Relational.

(OO2RL).

O1 ON

R1 RN Relational Layer.

(RRL)

PostgreSQL Oracle

Conversion Layer. (CL)

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

4.1.2. Implementation

The model has the following layers:

Application

Fuzzy Data Types Fuzzy Domains Fuzzy

Constraint

ValidatorValues Labels Constraint

Fuzzy Data

Types Adaptor

Fuzzy Domain

Adaptor

Hibernate Core

Database

Type 2 Type 3

Representation

Layer (OORL)

Adaptation

Layer (OO2RRL)

& (RRL)

Conversion

Layer (CL)

F

S

Q

L

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

Architecture with the FVP support:

Application

Hibernate FVP

Hibernate FSQL

Hibernate

Database

The Hibernate FSQL allows the representation andquerying of objects with fuzzy attributes.The Hibernate FVP layer allows the use of FuzzyValidity Periods.

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

4.2. Fuzzy Querying

The model uses the following elements:

• Declarative implementation for each fuzzyoperator. This implementation should be donein the SQL language.

• Abstract syntax tree (AST) representa-tion for the query. These representation allowsa customization process done by the conversionlayer (CL).

• Conversion Layer: This layer customizes theAST for the running database.

The implementation of the fuzzy querying is done bymodifying the HQL language. The fuzzy operatorsare implemented in a declarative way in the SQLlanguage.

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

Query translation:

SELECT

c,c1

Customer

c.fvp c1.fvp

contains

HQL sentence:

"SELECT c

FROM Customer c,

Customer c1

WHERE c.fvp

contains c1.fvp"

SQL sentence

"SELECT *

FROM Customer as c,

Customer as c1

WHERE 1 < CASE WHEN

(c.fvp.gamma <= beta2)

OR (c.fvp.beta >= gamma2) THEN 0

WHEN (c.fvp.alpha = alpha2) THEN 1

WHEN (c.fvp.gamma > beta2) AND

(c.fvp.alpha < alpha2)

THEN (c.fvp.gamma - beta2) /

( c.fvp.delta - delta2 )

ELSE (gamma2 - c.fvp.beta) /

( c.fvp.delta + delta2 );"

FROM

WHERE

Translation Customization

• The framework builds an abstract syntax tree(AST) once the query passed lexical and syntac-tical analysis.

• The AST represents tokens as nodes. The se-mantic analyzer renders the tree in the into SQLsentences. Then the dialect customizes the SQLsentence.

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

Example:

ID Name Salary BossID FVP001 Josh 1200 C [10/10/2009,27/10/2009,19/10/2010,27/10/2010]001 Josh 1500 B [19/10/2010,27/10/2010,-,-]002 Robert 800 A [14/05/2007,25/05/2007,17/01/2008,30/01/2008]002 Robert 1200 A [17/01/2008,30/01/2008,24/05/2009 ,30/05/2009]002 Robert 1400 A [24/05/2009,30/05/2009,28/10/2010,30/10/2010]003 Alex 2100 - [02/05/2007,15/05/2007,-,-]004 Tyna 1300 002 [25/07/2009,30/7/2009,15/10/2009,25/10/2009]005 Rose 2300 003 [25/09/2010,30/09/2010,25/02/2011,30/02/2011]

”Find all the employees with the boss 002 during the same period oftime.”

SELECT e,f FROM Employee e, Employee f WHERE e.ID="002"

AND e.ID<>f.ID AND e.fvp EQUALS f.fvp;

e.ID e.name f.ID f.name Comp.001 Josh 004 Tyna 0, 55

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

5. Conclusions and FutureWork

• We introduced a framework for the representa-tion of fuzzy types and for fuzzy querying.

• The implementation within Hibernate is basedon the portability.

• The drawback for the portability is the depen-dency between the application and the frame-work.

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

Future work:

• Fuzzy querying: bipolar specification in thequeries

• Applications in historical databases: the time isusually not precisely known.

• New fuzzy temporal representation: representa-tion for Fuzzy Validity Periods and implementa-tion of temporal comparisons within the Allen’srelations.

Contents

Motivation

Context

Proposal

Example

Comparison


Home Page

Title Page

JJ II

J I

of 37

Go Back

Full Screen

Close

Quit

Thank you!

Questions?

Contact:

[email protected]