Semantic Access: Semantic Interface for Querying Databases

Naphtali Rishe, Jun Yuan, Rukshan Athauda, Xiaoling Lu, Xiaobin Ma, Alexander Vaschillo, Artyom Shaposhnikov, Dmitry Vasilevsky, Shu-Ching Chen

High Performance Database Research Center

School of Computer Science

Florida International University

Demonstration OutlineDemonstration Outline

• Semantic Binary Object-Oriented Database System (Sem-ODB) and Semantic SQL.– Sem-ODB Engine.

– Semantic SQL Interpreter.

– ODBC Driver for Sem-ODB.

• Semantic Wrapper over Relational Databases.– Access Semantic Wrapper via native APIs

– Access Semantic Wrapper via ODBC.

• CORBA Compliant Components.

System ArchitectureSystem Architecture

catalog of database schemas Query Dispatcher

User’s Semantic SQL queries

Semantic Database Engine

meta-data

queries / query results

QUERY COORDINATOR

RELATIONAL SITE

SEMANTIC SITE

Semantic SQL Semantic Schema

Native C++/Java API

SDB-SQL Engine

CORBA

Commercial RDBMS

DBA

Semantic SQL Semantic Schema

Translator KDBTool

Knowledge Base

ODBC

Part I: SemODB and Semantic SQLPart I: SemODB and Semantic SQL

• More expressive data model

• Directly supports conceptual data model of the enterprise

• Shorter application design and programming cycle

• Empowers end-users to pose complex ad hoc decision support queries

Semantic Data Model(Sem-ODM)Semantic Data Model(Sem-ODM)BenefitsBenefits

Semantic Views over Relational Schemas– Higher level data model– Semantic view mirrors real world– Flexible classification of objects– Complex relations made simple: arbitrary

relationships– Semantically-Enhanced Object-Relational– Information in its Natural Form

Semantic-Views• Data is described at conceptual

level.

• Meaning of Information is Stored

• Relationships Between Categories

• Easier to formulate query Any Relationship CAN be

queried. Joins are NOT required to be

defined explicitly.

RDBMS• Data is described at logical level.

• Meaning of Information is Lost

• Relationships not Supported

• Complex queries have to be pre-programmed “Joins” are required to be

defined explicitly.

Semantic Data Model(Sem-ODM)Semantic Data Model(Sem-ODM)Benefits (Cont.)Benefits (Cont.)

(m:m)

manufactures

PRODUCTspecification: String m:mweight_kg: Number m:m

COMPANYname: String m:m

address: String m:m

Semantic View:

PRODUCTPID_key: string

COMPANYCID_key: string

Equivalent Relational Schema:

Semantic Data ModelSemantic Data ModelBenefits (cond.): Example schemasBenefits (cond.): Example schemas

COMPANY_ADDRESSCID_in_key: string

Address_in_key: string

COMPANY_NAMECID_in_key: string

Name_in_key: string

PRODUCT_SPECPID_in_key: stringSpec_in_key: string

PRODUCT_WEIGHTPID_in_key: string

WeightKG_in_key: number

MANUFACTURESCID_in_key: stringPID_in_key: string

Semantic SQLSemantic SQLFeaturesFeatures

• Semantic SQL

– Querying data at conceptual level

– Easier query facility

– ODBC/SQL Compliance

Semantic SQL Semantic SQL BenefitsBenefits

• Easier query facility (i.e. much shorter queries)

• Do not require to specify joins with the existence of relations in the semantic schem

Semantic SQL Benefits (cond.): Example query

PROJECTname: String key

description: Stringcomments: String

starting-date: Dateending-date:Date

LOCATIONnorth-UTM: Number key/2east-UTM: Number key/2

elevation-ft: Numberdescription: String

PHYSICAL OBSERVATION

STATION

is-part-of m:1:structure: Stringcomments: Stringhousing: String

FIXED STATIONplatform-height-ft: 0..50.000

ORGANIZATIONis-part-of m:m:name: String key

description: String MEASUREMEMENTTYPE

name: String keymeasurement-unit: String

upper-limit: Numberlower-limit: Number

IMAGEimage: Raw

subject: Stringdirection-of-view: 0..360

comments: Stringtype: Char(3)

OBSERVATIONtime: Date-timecomment: String MEASUREMENT

value: Number

by(m:1)

of(m:1)

located at(m:1)

serves(m:m)

runs(m:m)

belongs to(m:m)

Semantic View

RELATIONAL SCHEMA

Semantic SQLSemantic SQL Benefits (cond.): Example query Benefits (cond.): Example query

Select OBSERVATION__, of__, LOCATION from OBSERVATION where time > '1993/01'

Semantic SQL Query:

( select MEASUREMENT-TYPE.*, LOCATION.north-UTM-in-key,LOCATION.east-UTM-in-key, MEASUREMENT.*, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL from MEASUREMENT-TYPE, LOCATION, MEASUREMENT where time > '1993/01' and exists ( select * from FIXED-STATION where by-physical-observation-station-id =physical-observation-station-id-key and located-at--north-UTM =north-UTM-in-key and located-at-east-UTM = east-UTM-in-keyand of--name = name-key)) union ( select MEASUREMENT-TYPE.*, NULL, NULL, MEASUREMENT.*, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL from MEASUREMENT-TYPE, MEASUREMENT where time > '1993/01' and not exists ( select * from FIXED-STATION where by-physical-observation-station-id =physical-observation-station-id-key and of-name = name-key)) union ( select NULL, NULL, NULL, NULL, LOCATION.north-UTM-in-key, LOCATION.east-UTM-in-key, NULL, NULL, NULL, NULL, NULL, NULL, IMAGE.* from LOCATION, IMAGE where time > '1993/01' and exists ( select * from FIXED-STATION where by-physical-observation-station-id =physical-observation-station-id-key and located-at-north-UTM =north-UTM-in-key and located-at—east-UTM = east-UTM-in-key)) union ( select NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, IMAGE.* from IMAGE where time > '1993/01' and not exists ( select * from FIXED‑STATION where by--physical-observation-station-id =physical-observation-station-id-key))

SQL for RDBMS {“GIVE ME ALL OF THE OBSERVATIONS, WITH ALL OF THEIR ATTRIBUTES, SINCE JANUARY 1, 1993, AND THE LOCATION OF THE OBSERVING STATIONS”

Semantic SQLSemantic SQL Benefits (cond.): Example query

Sem-ODB ArchitectureSem-ODB Architecture

Semantic SQLInterpreter

Semantic Schema

C++/Java API

Semantic Database Engine

Control Server

Existing Tools (MS QBE)

ODBC Driver

Database

Applications

USERS

Part II: Semantic Wrapper over Part II: Semantic Wrapper over Relational DatabasesRelational Databases

AN OPEN MIDDLEWARE SYSTEM THAT PROVIDES SEMANTIC VIEWS AGAINST LEGACY RELATIONAL

DATABASES

DefinitionDefinition

Legacy Applications

Native DBMS interfaces

New Applications

Semantic Schemas/ Semantic SQL

Commercial Relational

DBMS(e.g. Microsoft Access,

Microsoft SQL Server, Oracle, ... )

ODBC

Semantic Wrapper

Semantic WrapperSemantic WrapperHigh-level Architectural ViewHigh-level Architectural View

Features of Semantic WrapperFeatures of Semantic Wrapper

• Provides Semantic Binary Object-oriented Data Model for Relational Databases

• Provides a powerful query language: Semantic SQL

• Database autonomy

• Can function as a stand-alone application and/or be plugged into a heterogeneous multi-database system

• Portability

Part III: CORBA Compliant ComponentsPart III: CORBA Compliant Components

• CORBA compliant components– Sem-ODB– Semantic Wrapper.

• Platform and network level heterogeneity is resolved by using CORBA architecture.

• Common CORBA IDL provides semantic access to both relational and semantic databases.

• Sem-ODM view against each data source.

SummarySummary

• Sem-ODM: an expressive data model.• Sem-ODB: a robust database engine.• Semantic SQL: an intelligent and easier query

language.• Semantic Wrapper: a portable, autonomous,

stand-alone/ multi-database component tool for legacy databases.

• Semantic Access via ODBC.• CORBA compliant components.