management of the evolution of database-centric information systems
DESCRIPTION
Management of the Evolution of Database-Centric Information Systems. Panos Vassiliadis 2 , George Papastefanatos 1 , Timos Sellis 1 , Yannis Vassiliou 1 1 National Technical University of Athens-KDBMS Laboratory {gpapas , timos , yv}@dblab . ece . ntua . gr 2 University of Ioannina - PowerPoint PPT PresentationTRANSCRIPT
Management of the Evolution of Database-Centric Information
Systems
Panos Vassiliadis2 , George Papastefanatos1,
Timos Sellis1, Yannis Vassiliou1
1 National Technical University of Athens-KDBMS Laboratory
{gpapas,timos,yv}@dblab.ece.ntua.gr2 University of Ioannina
P.Vassiliadis, G.Papastefanatos, T.Sellis, Y. Vassiliou. Management of the Evolution of Database-Centric Information Systems PresDB ’07, Edinburgh, 2007
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Database Schema Evolution
Current database systems are continuously evolving environments, where design constructs are
AddedRemovedModified
Evolution is not handled by current DBMS with an automatic way
E.g., syntactic as well as semantic adaptation of queries and views: time-consuming task, treated in most of the cases manually
Evolution driven database design is missing
P.Vassiliadis, G.Papastefanatos, T.Sellis, Y. Vassiliou. Management of the Evolution of Database-Centric Information Systems PresDB ’07, Edinburgh, 2007
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Empirical Studies Empirical Studies on Database on Database
Schema EvolutionSchema Evolution
Principled Principled Response to Response to evolutionary evolutionary
eventsevents
Design PatternsDesign Patterns
Principled Principled Description of the Description of the architecture of a architecture of a database-centric database-centric
Information Information SystemSystem
MetricsMetrics
EvolvingDatabaseSystems
Issues in Database Schema Evolution
P.Vassiliadis, G.Papastefanatos, T.Sellis, Y. Vassiliou. Management of the Evolution of Database-Centric Information Systems PresDB ’07, Edinburgh, 2007
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Empirical Studies on Database Schema Evolution
Collect test cases to come up with fundamental laws that govern database evolution
Establish an experimental protocol for monitoring existing real-world databases and discover the way they evolve
Collect such results and make them available to the research community
Empirical Empirical Studies on Studies on Database Database Schema Schema
EvolutionEvolutionPrincipled Principled
Response to Response to evolutionary evolutionary
eventsevents
Design PatternsDesign Patterns
Principled Principled Description of Description of
the architecture the architecture of a database-of a database-
centric centric Information Information
SystemSystem
MetricsMetrics
EvolvingDatabaseSystems
P.Vassiliadis, G.Papastefanatos, T.Sellis, Y. Vassiliou. Management of the Evolution of Database-Centric Information Systems PresDB ’07, Edinburgh, 2007
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Principled Description of the architecture of a database-centric Information System
A commonly agreed formalism to express the internals of a database-centric system
a model of the structural properties and dynamics of database-centric systems interdependencies in the components of a complex database-centric system a scientific foundation for the architecture of complex database-centric systems
Empirical Empirical Studies on Studies on Database Database Schema Schema
EvolutionEvolutionPrincipled Principled
Response to Response to evolutionary evolutionary
eventsevents
Design PatternsDesign Patterns
Principled Principled Description of Description of
the architecture the architecture of a database-of a database-
centric centric Information Information
SystemSystem
MetricsMetrics
EvolvingDatabaseSystems
P.Vassiliadis, G.Papastefanatos, T.Sellis, Y. Vassiliou. Management of the Evolution of Database-Centric Information Systems PresDB ’07, Edinburgh, 2007
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Principled Response to evolutionary events
Forecast the impact of an evolution event Handle conflicts Keep versions of the database consistent to user
views Treat evolution in the presence or absence of user
requirements Automation of the reaction to changes
self-monitoringimpact predictionauto-regulation
self-repairing
Empirical Empirical Studies on Studies on Database Database Schema Schema
EvolutionEvolutionPrincipled Principled
Response to Response to evolutionary evolutionary
eventsevents
Design PatternsDesign Patterns
Principled Principled Description of Description of
the architecture the architecture of a database-of a database-
centric centric Information Information
SystemSystem
MetricsMetrics
EvolvingDatabaseSystems
P.Vassiliadis, G.Papastefanatos, T.Sellis, Y. Vassiliou. Management of the Evolution of Database-Centric Information Systems PresDB ’07, Edinburgh, 2007
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Metrics
Measures for the quality of the design of a database wrt its evolution
“Right” families of such measuresEmpirical Empirical
Studies on Studies on Database Database Schema Schema
EvolutionEvolutionPrincipled Principled
Response to Response to evolutionary evolutionary
eventsevents
Design PatternsDesign Patterns
Principled Principled Description of Description of
the architecture the architecture of a database-of a database-
centric centric Information Information
SystemSystem
MetricsMetrics
EvolvingDatabaseSystems
P.Vassiliadis, G.Papastefanatos, T.Sellis, Y. Vassiliou. Management of the Evolution of Database-Centric Information Systems PresDB ’07, Edinburgh, 2007
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Design Patterns
Come up with a well-founded theory for design patterns wrt evolution
Eliminate maintenance traps due to ad-hoc, or complex solutions
Methods for testing database designs Empirical Empirical
Studies on Studies on Database Database Schema Schema
EvolutionEvolutionPrincipled Principled
Response to Response to evolutionary evolutionary
eventsevents
Design PatternsDesign Patterns
Principled Principled Description of Description of
the architecture the architecture of a database-of a database-
centric centric Information Information
SystemSystem
MetricsMetrics
EvolvingDatabaseSystems
P.Vassiliadis, G.Papastefanatos, T.Sellis, Y. Vassiliou. Management of the Evolution of Database-Centric Information Systems PresDB ’07, Edinburgh, 2007
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Database Schema Evolution – Our approach
Mechanism for performing what-Mechanism for performing what-if analysis for potential changes of if analysis for potential changes of
database configurationsdatabase configurations
Evolving databases
QueriesDatabase Schema
Graph-based modeling
for uniform representation
Rules for Handling Evolution
Metrics for Evaluating Evolution
Design
Evolving applications
Graph based representation of Graph based representation of database constructs (i.e., database constructs (i.e., relations, views, constraints, relations, views, constraints, queries)queries)
Annotation of graph with rules Annotation of graph with rules for adapting queries to database for adapting queries to database schema evolutionschema evolution
P.Vassiliadis, G.Papastefanatos, T.Sellis, Y. Vassiliou. Management of the Evolution of Database-Centric Information Systems PresDB ’07, Edinburgh, 2007
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Graph based representation
Q: SELECT EMP.Emp#, Sum(WORKS.Hours) as T_Hours
FROM EMP, WORKS
WHERE EMP.Emp# = WORKS.Emp#
GROUP BY EMP.Emp#
P.Vassiliadis, G.Papastefanatos, T.Sellis, Y. Vassiliou. Management of the Evolution of Database-Centric Information Systems PresDB ’07, Edinburgh, 2007
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Annotation of graph with rules for adapting queries to database schema evolution
Set of evolving database constructs:• relations• attributes• constraints
Set of potential evolution changes: • addition• deletion• modification
Set of reaction policies: • propagate• block• prompt
According to prevailing policy, the proper action is taken graph transformation
P.Vassiliadis, G.Papastefanatos, T.Sellis, Y. Vassiliou. Management of the Evolution of Database-Centric Information Systems PresDB ’07, Edinburgh, 2007
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An Example
from
map-select
S
Q
SS
EMP
Emp# NameEmp#
NameS
map-select
...
On attribute addition To EMPTHEN propagate
Annotated Query Graph Event
Add attribute Phone to EMP relation
Phone
from
map-select
S
Q
S SS
EMP
PhoneEmp# NameEmp#
NameS
map-select
...
On attribute addition To EMPTHEN propagate
S
map-select
Transformed Query Graph
P.Vassiliadis, G.Papastefanatos, T.Sellis, Y. Vassiliou. Management of the Evolution of Database-Centric Information Systems PresDB ’07, Edinburgh, 2007
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Conclusions – Future Work
A tool for visualizing and performing what-if analysis for several evolution scenarios.
SQL extensions for annotating graph constructs with evolution semantics
Evolution-driven database designDesign patterns for allowing smooth evolutionDefinition of graph based metrics evaluating the system design