R E S EA R C H G R O U P
In fo rm at io n M an agem en t
Chapter 2
Database System Concepts and
Architecture
Computer Science Centre
University of Indonesia
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Evolution of computing
• Database has evolved since nearly
every stage of computing, from:
– mainframes, which are monolithic
– Client-server
– Web-based
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Data Models
• A collection of concepts used to
describe the structure of a database
– Data types
– Relationships
– Constraints
– Etc
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Categories of Data Models
• Conceptual data models: high level
• Physical data models: how data is
actually stored in a disk
• Representational data models:
somewhere between those two… let’s
see…
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Representational data model
• Relational data model (our main
discussion in this class)
• Network data model (uses directed
graphs)
• Hierarchial data model (history…)
• Object data model (this is new!)
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Database schemas
• Schemas: description of the database, but not the database
itself!
• Example of a schema diagram:
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• Not included in the schema diagram
above:
– Data types?
– Relationships?
– Constraints, such as “students in CS major
must take CS1310…”
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Database states
• Also called ‘snapshot’
• After we define, generaly a database is
at the ‘empty state’
• We get the ‘initial state’ after we first
load the database
• Valid state is a state which satisfies the
structure and constraints in the schema
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Three Schema Architecture
• Internal schema: describes the physical
storage structure of the database
• Conceptual schema: structure of the
whole database for a community of
users
• External schemas for user views
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R E S EA R C H G R O U P
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Data Independence
• Logical data independence: we can
change the conceptual schema without
changing the application program
• Physical data independence: we can
change the internal schema without
changing the conceptual schema. It
might be because file database must be
reorganized for fine tuning.
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Database Languages
• Data definition language
• View definition language
• Data manipulation language
– High level: SQL, set-at-a-time processing
– Low level: VB, COBOL, record-at-a-time
processing
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DBMS Interfaces
•
•
•
•
Menu based interface
Forms based interface
Graphical user interface
Natural language interface, you can
ask, “Show me all the students with
GPA > 3”
• Parametric interface, such as xBase
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Database utilities
•
•
•
•
Loading utility, or importer
Backup utility, usually to tape
File optimizer or reorganizer
Performance monitoring: fragmentation,
load balancing, etc.
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Classification of DBMS
•
•
•
•
•
Single user vs multi user
Centralized vs distributed
Price…!
OLTP support?
OLAP support (read page 842)
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Group Assignment
Comparative Study of Popular
DBMS
Computer Science Centre
University of Indonesia
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Which ones?
Group 1 (Haswar, Conna,
Vicky)
• MySQL
• MS-SQL Server
• FoxPro
Group 3 (Danu, Lia,
Narpati)
• Oracle database
• Postgres
• Borland Interbase
Group 2 (Fitri, al-Harith,
Avi)
• MySQL
• MS-SQL Server
• IBM DB2
Group 4 (Armand, Tia,
Aryo)
• FoxPro
• MS-Access
• Informix
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What to look for
• Use theories in chapter 1 & 2!
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Deliverables
• Presentatoin (of course)
• Due next week
• Paper, submitted to the TAs: Elan and
Amir (again…!)
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Chapter 2