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19 Cards in this Set
- Front
- Back
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Define File-Based Systems |
A collection of application programs that perform services for the end-users, such as the production of reports. Each program defines and manages its own data. |
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Limitations of file-based systems |
-Separation and isolation of data -Duplication of data -Data dependence -Incompatible file formats -Fixed queries/proliferation of application programs |
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Define Database |
A shared collection of logically related data and its descriptions, designed to meet the information needs of an organization |
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Define DBMS |
A software system that enables users to define, create, maintain, and control access to the database. |
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Define Data Definition Language (DDL) |
Allows users to specify the data types and structures and the constraints on the data to be stored in the database. |
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Define Data Manipulation Language (DML) |
Allows users to input, update, delete, and retrieve data from the database. |
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Describe Views |
Views are essentially a subset of the database. They provide a level of security (can hide certain information from particular users), provide a mechanism to customize the appearance of the database (example, can rename fields to more applicable names), and can present a consistent, unchanging picture of the structure of the database (if fields are added, removed, or changed that are unused by a view, the view is unchanged). |
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What are the five major components of a DBMS environment? |
Hardware (machine) Software (machine) Data (bridge) Procedures (human) People (human) |
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Role: Data Administrator |
Responsible for the management of the data resource, including database planning; development and maintenance of standards, policies and procedures; and conceptual/logical database design. |
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Role: Database Administrator |
Responsible for the physical realization of the database, including physical database design and implementation, security and integrity control, maintenance of the operational system, and ensuring satisfactory performance of the applications for end users |
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Role: Database Designers |
Two Types. Logical Database Designer: concerned with identifying the data (entities and attributes), relationships between the data, and the constraints of the data to be stored in the database. Physical Database Designer: decides how the database is to be physically realized, which involves mapping the logical database design into a set of tables and integrity restraints, selecting specific storage structures and access methods for the data to achieve good performance, and designing any security measures required on the data |
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Role: Application Developers |
Work from specifications produced by systems analysts. Each program contains statements that request the DBMS to perform some operations on the database, which includes retrieving, inserting, updating, and deleting data. |
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Role: End Users |
Two types. Naive: Unfamiliar with the structure of the database. Uses applications to access data as simply as possible. Sophisticated: Familiar with the structure of the database and facilities offered by the DBMS. May use high-level query languages to perform operations or even write applications themselves. |
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Advantages of DBMS |
Control of data redundancy Data consistency More info from same amount of data Sharing of data Improved data integrity Improved security Enforcement of standards Economy of scale Balance of conflicting requirements Improved data accessibility and responsiveness Increased productivity Improved maintenance through data independence Increased concurrency Improved backup recovery service |
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Disadvantages of DBMS |
Complexity Size Cost Hardware costs Cost of conversion Performance Greater impact of failure |
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Define Data |
Representation of observations or concepts suitable for communication, interpretation, and processing by humans or machines. |
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Define Information |
Data that have been processed and can be used for a decision making |
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Define Informatics |
The science of information. It studies the representation, processing, and communication of information in natural and artificial systems. |
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Define Knowledge |
The facts acquired after processing information |
