H ECATAEUS A Framework for Representing SQL Constructs as Graphs George Papastefanatos 1, Kostis Kyzirakos 1, Panos Vassiliadis 2, Yannis Vassiliou 1 1

HECATAEUS

A Framework for Representing SQL Constructs as Graphs

George Papastefanatos1, Kostis Kyzirakos1,

Panos Vassiliadis2, Yannis Vassiliou1

1 National Technical University of Athens-KDBMS Laboratory

{gpapas,kkyzir,yv}@dbnet.ece.ntua.gr2 University of Ioannina

{[email protected]}

G.Papastefanatos, K.Kyzirakos, P.Vassiliadis, Y. Vassiliou. A Framework for Representing SQL Constructs as Graphs EMMSAD’05, Porto, 2005

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Outline

Background & Motivation A Graph-based Model for SQL Constructs Implementation of the Framework Case study: Modeling TPC-C benchmark Conclusions and Future Work


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Outline



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Contribution

A graph modeling framework that uniformly covers relational tables, views, database constraints and SQL queries

An implementation of the framework, named HECATAEUS.


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Why bother modeling SQL queries as graphs?

Visualization and analysis of both the structure and the workload of the system

Forecasting of the impact of changes Evaluation of the quality of the database design

Framework stakeholders Database Administrators Database Designers / Developers


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Motivation Queries Evolution

Which part(s) of the system is (are) affected if we delete an attribute and how?

Performance Which part(s) of the system has (have) the most

workload? Database Analysis and Quality Evaluation

Which tables are correlated the most ? Is design A better than design B and why?


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Background Traditional database modeling techniques, like ER

diagrams, focus on conceptual level modeling. Visual Query Languages – Visualization

techniques Graph-based Icon-Based Diagram-Based


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Outline



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Graph Model

A graph modeling technique that uniformly covers relational tables, views, database constraints and SQL queries

Directed Labeled Graph Relations Conditions Queries/Views


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Graph Model (continued)

The proposed modeling technique represents all the aforementioned database parts as a directed labeled graph with specific types of nodes and edges for each database part and relationship.

Graphs are employed as a modeling technique because they can address the large size and complexity that characterize a database schema.


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Representing Relations

Relation: EMP(Empid, Name, Salary)


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Representing Conditions

Primary Key on EMPID Query conditionSELECT EMPID, NAMEFROM EMPWHERE AGE>30 AND SALARY>5000;WHERE AGE>30 AND SALARY>5000;


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SELECT EMP.EMPID,Sum(WORKS.Hours) as T_HoursFROM EMP, WORKSWHERE EMP.EMPID = WORKS.EMPIDGROUP BY EMP.EMPID;

Representing Queries


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SELECT EMP.EMPID,Sum(WORKS.Hours) as T_Hours

Representing Queries - SELECT Subgraph


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FROM EMP,WORKS

Representing Queries – FROM Subgraph


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WHERE EMP.EMPID = WORKS.EMPID

Representing Queries - WHERE Subgraph


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GROUP BY EMP.EMPID

Representing Queries - GROUPBY Subgraph


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Outline



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HECATAEUS

Input Database schemas(DDL Files) Queries (SQL scripts)

Representation in the proposed graph model Dynamic Graph – Holds all the semantics for the

types of nodes and edges


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HECATAEUS Functionality Different views of the graph(zoom in zoom out) Subgraph Isolation/Highlighting Manipulation of the graph components(e.g. add edge/

remove node) Output graph to various formats (PostScript, SVG) Definition and application of graph algorithms and

metrics


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Architecture Parser Graph Manager Metrics Manager Catalog

DDL fileSQL script

DB Catalog

Parser

Create Tables

Graph Manager

Create Relation Graph

Create Query Graph

Validate Query

Metric Definition

Graph Algorithms Definition

Metrics ManagerInput

Visu

alization


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Development Platform

MS Visual Studio .NET Platform Parser and Catalog: SharpHSQL, an open-source

database in C#. Graph Manager and Metrics Manager: LEDA C++

libraries for .NET technology


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Outline



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Demo – Modeling TPC-C Benchmark


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Outline



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Conclusions Contributions

A graph modeling framework that uniformly covers relational tables, views, database constraints and SQL queries

An implementation of the framework, named HECATAEUS.

Potential Benefits Visualization of both the structure and the workload of the

system Evaluation of quality of Database Design Forecasting of the impact of changes


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Future Work - Research in Progress

Definition of Metrics and Algorithms for Evolution

Definition of Metrics for Design Quality Application of graph-theoretic metrics and

algorithms Reverse functionality. Automatic DDL and

SQL code creation from graphs Integration of Hecataeus with a Repository


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Thank you!

Many thanks to our hosts! (Muitos agradecimentos a nossos anfitriões!)

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Documents

H ECATAEUS A Framework for Representing SQL Constructs as Graphs George Papastefanatos 1, Kostis Kyzirakos 1, Panos Vassiliadis 2, Yannis Vassiliou 1 1