Relation database online version

Relation database online version - Relational Database...

Info icon This preview shows pages 1–13. Sign up to view the full content.

View Full Document Right Arrow Icon
Relational Database
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Agenda Database Management–An Introduction Relational Database Entity-Relationship Diagram Relation Data Model Conversion
Image of page 2
TYPICAL PROBLEMS WITH FILE-BASED SYSTEMS Organizational memory may be seen as a vast, disorganized data warehouse. Problems include: Redundancy: same data stored in different memories Data control: data not managed as a valuable resource Interface: difficult to access data Delays: long delays in responding to requests for data Lack of reality: data do not reflect the complexity of the real world Lack of data integration: data dispersed across different systems; also where data is stored may not be known.
Image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
File-Oriented Approach Application program #2 Application program #1 File # 1 Item A Item B Item C File # 2 Item B Item D Item E
Image of page 4
DATABASE APPROACH TO MANAGING PERSISTENT DATA The database approach emphasizes the integration and sharing of data across the organization.
Image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Database Approach Application program #3 Application program #2 Database management system Application program #1 Item A Item B Item C Item D Item E Database
Image of page 6
BENEFITS OF THE DATABASE APPROACH Redundancy can be reduced Thus, inconsistency can be avoided Integration of data Data can be shared among applications Standards can be enforced by the DBA formats, representation, naming, documentation Security restrictions can be applied
Image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
BENEFITS OF THE DATABASE APPROACH Data independence Broadly -- the immunity of applications to change in storage structure and access technique Logical -- capacity to change conceptual schema without changing application programs (e.g., adding an attribute or an entity type) Physical -- capacity to change internal schema without having to change external or conceptual schema (e.g., creating additional access structures to improve retrieval performance) Ease of Application Development Data accessibility and responsiveness enhanced Reduced program maintenance
Image of page 8
SOME DEFINITIONS What is a database? a shared collection of logically related persistent data , designed to meet the needs of multiple users usually within an organization. What is a database management system? DBMS is a collection of programs that enables users to define, construct and manipulate a database. (More detailed defn. later). What is a database system?
Image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
STEPS IN DATABASE DEVELOPMENT PROCESS Analysis creation of the Entity-Relationship Model Design Logical Database Design creation of normalized relations Physical Database Design specification storage technology requirements specification/ creation of appropriate file structures
Image of page 10
Agenda Database Management–An Introduction Relational Database Entity-Relationship Diagram
Image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Relational Databases A data model is an abstract representation of the contents of a database.
Image of page 12
Image of page 13
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern