Reznichenko Valery
Organization of data and knowledge bases
Lecture 2. Data Base Architecture
National Aviation University
Computer Science Faculty
Department of Software Engineering
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Lecture 2. Data Base Architecture
CONTENTS
ANSI/SPARC architecture
Conceptual level
External level
Internal level
Mappings
Data base management system
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Lecture 2. Data Base Architecture
Different Meaning of «architecture»
Functional architecture
Software architecture
Hardware architecture
Network architecture
Implementation architecture
Information architecture
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Lecture 2. Data Base Architecture
Architecture ANSI/X3/SPARC
ANSI/X3/SPARC – Study Group on Data Base Management Systems
Areas of DB technology standardization
Only DB interfaces may be standardized
Interfaces DB architecture
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Lecture 2. Data Base Architecture
I n t e r f a c e s
External External model . . . External model schemas 
conceptual – external mappings
Conceptual |
Conceptual model of Application Domain |
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schema |
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conceptual – internal mapping |
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Internal |
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Internal model of Data Base |
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DBMS |
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schema |
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Storage structures of |
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OS |
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Lecture 2. Data Base Architecture
Conceptual Level
A uniform basis of understanding of AD
Includes only conceptually relevant aspects
Feature of allowed evolution of DB
Basis of mappings external-intenral levels
Supports the data independance
Supports centralized administration
Stability
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Lecture 2. Data Base Architecture
External Level
Convinient data representation
Promotes logical independance
Promotes data safety problem
Supports different external interfaces
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Lecture 2. Data Base Architecture
Internal Level
Provides DB adjustments
Supports data storage structures and access methods
DB efficiency, prformance, redundancy
Physical data independance
Promotes data safety problem
Mapping internal schema to the OS data structures
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Lecture 2. Data Base Architecture
Mappings
External-conceptual
Conceptual-internal
and vise-versa
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Lecture 2. Data Base Architecture
end users |
application |
sophisticated |
database |
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programmers |
users |
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administrator |
application |
application |
query |
database |
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interface |
programs |
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scheme |
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embedded |
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DML |
DDL |
object |
DML |
query |
compiler |
interpreter |
code |
precompiler |
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evaluation |
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engine |
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transaction |
buffer manager |
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manager |
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file |
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manager |
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indices |
statistical data |
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data files |
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data dictionary |
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