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DBMS ASSIGNMENT 01

NAME

- SAHEN SANOJA GALBADA LIYANAGE

SQA ID NO

-

NIC NO

- 922051160V

SUBJECT

- DATABASE MANAGEMENET SYSTEMS 01

SUBJECT CODE BRANCH

- COLOMBO

DATABASE
FUNDAMENTALS
FUNDAMENTALS, EVOLUTION AND JOB ROLES REVOLVING

S
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G
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4
Data vs information…………………………………………………………………………………………………………5
Database, DBMS and User…………………………………………………………………………………………5

Fundamentals of Database management systems

6

Evolution of Database management systems
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9
Database approach…………………………………………………………
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12
Database Administrator(DBA)……………………………………………………………………
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…13
Application Developer…………………………………………………………………
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14

References

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PAGE 3

Basic Definitions
Data - Known facts that can be recorded and have an implicit meaning
...
E
...
- alphabets, numbers or symbols
...
Information is often the result of combining, comparing, and performing
calculations on data
...
In one view, databases can be classified according to
types of content: bibliographic, full-text, numeric, and images
...
The relational database
was invented by E
...
Codd at IBM in 1970
...
The DBMS provides users and programmers with a systematic way to create,
retrieve, update and manage data
...


Early Database Application –
The Hierarchical and Networking Models were announced in
mid-1960 and conquered during the seventies
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1968 – Used Flat files to maintained data
...
g
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2) Weak security
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Relational DBMS Products developed in
the 1980’s
...
SQL (structured query language)
becomes “intergalactic standard”
...
Combination of
object-orientation in relational DBMSs, new application areas, such as data warehousing and
OLAP, web and Internet, Interest in text and multimedia, enterprise resource planning (ERP) and
management resource planning (MRP)
In 1991 Microsoft sends access, a personal DBMS made as element of Windows progressively
replaced all other personal DBMS products
...
A mad struggle ensues to allow remote entree to
computer systems with legacy data
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Major dealers begin to fit in XML into DBMS products
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Made commercial websites and
became very popular
...
g
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com, amazon
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com
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E
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-Bureau of Citizenship and
Immigration Services, Bureau of the Census
...


PAGE 8

DATABASE MANAGEMENT SYSTEMS APPROACH VS FILE
BASED SYSTEM APPROACH

File Based approach
A collection of application programs that perform services for the end-users such as the
production of reports
...


The structures are reliant on the application programming language
...

Duplicates data between applications
...
g
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Can create data inconsistencies
...

Application development time is rather than database system
...


Separation and isolation of data
...
Duplication of data


Same data is held by different programs



Wasted space and potentially different values and different formats for the same
item

3
...


All the above limitations of the file-based approach can be attributed to two factors:
1) The description of the data is embedded in the application programs, rather than being

[Cite your source here
...


2) There is no control over the access and manipulation of data beyond that imposed by the
application programs
...
What emerged were the database and
the Database Management System (DBMS)
...


Characteristics of Database approach
1) Self-describing nature of a database system


A DBMS catalog stores the description of a particular database
...
g
...




The description is called meta-data
...




Allows changing data structures and storage organization without having to
change the DBMS access programs
...


PAGE 10



Data abstraction - DBMS provides users with conceptual representation of data
(what we see on) without how the data is stored on physical drive
...
Each user may see a
different view of the database, which describes only the data of interest to that user
...
g
...


Advantages of the Database approach –
No data redundancy: Data is stores only one time, elimination data redundancy
and decreasing storage costs
...

Current values: A change to the database made by any user yields current data
values for all other users
...

Consolidation of data management – Just one software program DBMS to
manage access to the database
Security restrictions can be applied – Security features can be built into the
DBMS to restrict and protect the data
...


PAGE 11

Job roles related to database management systems

What is a roles database –
A roles database is a mechanism used to assign a user access to data or
applications
...
The DA consults with and advises senior
managers, ensuring that the direction of database development will ultimately support corporate
objectives
...

2) Database accessibility
3) Correct Performance issues
4) Correct capacity issues
5) Data replication
6) Table maintenance
 Data administrator carries a massive amount of responsibilities
...
The role of the DBA is more technically oriented than the role of the DA, requiring
detailed knowledge of the target DBMS and the system environment


Duties of Data Administrator –
1) Develop and enforce database standards, guidelines and operational policies
and procedures
...

3) Take care of the Database design and implementation
4) Implement and maintain database security (create and maintain users and
roles, assign privileges)
5) Review necessary storage media (DASD and Tape)
6) Review SQL performance and tuning
7) Review backup and recovery strategies
8) Review where required, the purge/archive criteria
9) Monitoring database/subsystems performance issues
10) Review migration plans

Database Designer (DD) –
In large database design projects, we can distinguish between two
types of designer: logical database designers and physical database designers
...

The logical database designer must have a thorough and complete understanding of the
organization’s data and any constraints on this data
...
This involves:
1) Mapping the logical database design into a set of tables and integrity constraints
...

3) Designing any security measures required on the data
...
This is
the responsibility of the application developers
...
Each program contains statements that request the
DBMS to perform some operation on the database
...


End User (EU) –
The end-users are the ‘clients’ for the database, which has been
designed and implemented, and is being maintained to serve their information needs
...
End users are in a separate group
from the installers or administrators of the product
...
programmerinterview
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php/database-sql/database-roles/



Fundamentals of Database management systems by Asthar kapoorn
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wikipidia
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D

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